I've answered this question a couple times now, so I thought I'd make a post here and list all the places I find in Akihabara in Tokyo, Japan, so if anyone else is heading there on holiday etc, there is a central list of places to check out for electronics etc.
I'll add to this list as I find/remember more places to check out.
Also, Monday seems to be the day many stores are closed (they are open on the weekend instead, so Monday is their 'holiday'), so although many stores are open every day, some of these smaller stores are likely to be closed then.
Tokyo Radio Department Store:Multiple floors of parts shops to rummage through.
https://goo.gl/maps/P4f8b67sjaKBe73a6https://www.tokyoradiodepart.co.jp/index.htmlKeisokuki-land:High end test gear and second hand stuff, no bargains to be had though, even their 2nd hand stuff is sold at a premium...
Good to take a look, but the prices are squarely in the "Oh, you need this old thing to keep your production process running? Pay up sucker" territory. But they do come with full warranty and are fully tested.
They sell new Rigol, Fluke, Keysight, R&S, Tektronix, GW Instek and Hioki etc. at market rates too. (But no Siglent

).
https://goo.gl/maps/RxHa6c7Fpa8goLSx6http://www.keisokuki-land.co.jp/Radio Center:Lots of stuff in here right next to the station. Lots of stores inside and out. Fluke, Yokogawa, etc. Along with transformers, cables, hand tools, components, connectors and second hand stuff. Be sure to check it out thoroughly and head up to the second floor for more stuff.
There is also a second hand consignment type store full of shelves divided into boxes that are great to look through for random second hand electronic and electrical gear and other random stuff.
https://goo.gl/maps/xMdKJYFVViPSwhu1Ahttp://www.radiocenter.jp/Sengoku:4-ish floors (inc. basement) plus the location where Nishikawa (below) used to be, with all sorts of electronics parts and tools. Awesome shop to check out and one of the larger ones so there's a lot of stuff. They have Raspi, Sparkfun, Adafruit, general and audio parts and enough stuff to build your own electric guitar with the amp too.
2nd floor of the old Nishikawa store location is the place to check for guitar aficionados.
https://www.sengoku.co.jp/Main Store:https://goo.gl/maps/FvY5ayRrHFfxPH7KA - Basement: Components - Connectors, Resistors, Chips, Fans, Fuses, Capacitors, etc etc.
- 1st floor: Tools, Raspberry Pi, Arduino, Sparkfun, Modules, Multimeters and leads, 3D printers, etc.
- 2nd floor: Cable, nuts and screws etc, metal stock, other hardware etc.
- 3rd floor: LED's, globes, enclosures, educational and hobby kits, enclosures, mechatronics parts, battery holders, etc.
Second store (Previously Nishikawa):https://maps.app.goo.gl/WTU29wHbVMVKRTtz9 - 1st floor: Cables of all types, USB, DC Jacks and PSU's, GPIB, PC Cables, AV cables, etc, etc. More cables than you can think of. Also arcade controller parts too.
- 2nd floor: Guitar parts.
Akizukidenshi:Another electronics parts shop. LED's, semiconductors, passives, Raspi, Arduino, microcontrollers and programmers etc. They also have a few tools and meters, including the Der-EE DE-5000 LCR meter and all accessories on the shelf for a good price (Competitive with ebay even), if you ask, they might even have a carry case out the back (I got one recently).
Also, be sure to check the 2nd floor too. Exit the 1st floor and you'll see an entrance just to the left as you look back towards the building from the street, head up the stairs to the 2nd floor for more stuff (including a few boxes of random surplus that they often have sitting there in tubs).
You'll find PicoScopes here if you need one of them too.
https://goo.gl/maps/7cNGqVNiM1qD8YkP7http://akizukidenshi.com/catalog/default.aspxAkiba LED:Well stocked LED store, not so competitive vs online, but if you need an LED now, he probably has it.
https://g.page/pikarikan?sharehttps://www.akiba-led.jp/Marutsu:Parts and tools, they sell a lot of Digikey/RS/Adafruit/Sparkfun stuff too.
https://goo.gl/maps/tkaUkDP4EkPGciYv6https://www.marutsu.co.jp/Nishikawa Electric Parts:
Nuts, bolts, fasteners etc of all sorts and hand tools on the 1st floor, connectors and tools on the 2nd floor.
Need some machine screws or a small connector? This is the place to check first.
https://goo.gl/maps/mBssS8yWSVVL6VY37
http://nishikawa.or.tv/index.html(See Sengoku)
Fuji Musen:Antenna, radios and RF stuff on 1st and 2nd floors (Head into the back of the 1st floor for the stairs to 2nd floor) and retro video games at super potato on the upper floors, accessed from the right side of the building, you'll see the signs.
https://goo.gl/maps/gok78xs1trJGYu2AAhttp://www.fujimusen.com/Classic Components:Possibly Japan's largest tube store. A huge selection of tubes and other stuff like capacitors, sockets, transformers, etc.
Definitely worth a look if you have even a passing interest in tubes and the like.
https://goo.gl/maps/iko3Ji2Y98EsbiHv6http://userweb.pep.ne.jp/classic/open.htmTomoca:As you exit the gates on the 'Electric Town' side of Akihabara station, turn left to the street.
Just down the street to the right you'll see 'Akihabara Radio Kaikan' adjacent to the building with the escalators on the front.
Battle your way through the anime merchandise up the escalator to the 2nd floor and turn left.
They sell pro audio and PA gear (Mics, cables mixing desks, lighting, etc), also lots(!) of audio/RF connectors and cable including Amphenol, Canare, Belden, Neutrik etc, etc.
They also sell hand tools, cable by the meter, and even DeOxit too.
They are also on the 3rd floor of the Tokyo Radio Department Store with connectors, fans, 'wall wart' power supplies and NiCd/NiMh/Lithium batteries.
https://goo.gl/maps/adnowBrGK7zTZ8Ms5http://www.tomoca.co.jp/Koizumi-Musen:Amplifiers, tubes, speakers, parts etc.
https://goo.gl/maps/VE7A97kQ2ZsUmYn58http://www.koizumi-musen.com/Kasuga Musen:Amplifiers, tubes, speakers, parts etc.
https://goo.gl/maps/pMCY86o3fZyFV4xFAhttp://www.e-kasuga.net/Nichibei Shoji:Full of random electronics surplus and junk, the occasional bit of old test gear and often a really good deal on whatever happens to be there at the time.
Don't bother going here though, it's my favourite junk store so I want all the goodies for myself.
https://goo.gl/maps/JQjj8H1krxJML5xz5https://my-site-105174-102944.square.site/https://twitter.com/superjunkNBS?Oyaide Denki:Lots of audio and other cables, connectors, 'audiophile grade' power outlets and plugs etc. (If you want to pay too much for a carbon fiber wall outlet with gold plated contacts, this is your store).
They sell silver solder too, which is useful.
https://g.page/oyaide_denki?sharehttp://www.oyaide.com/ENGLISH/index.htmlYamada DenkiThis is the largest general electrical/electronics/whitegoods/etc store in Japan.
They have everything you could dream of when it comes to computer parts, TV's, Stereos, Camera gear(!), Fridges, appliances, etc.
Check out the 'International' section for stuff in 230V and 115V versions if you want an awesome rice cooker or one of those Japanese heated toilet seat with built in bidet or the like.
On the upper floors is the audio stuff with tubes and other 'audiophile' grade stuff. If you want to audition a set of Dynaudio speakers, then see a 4K projector and buy some expensive tubes, come here.
They do have some reasonable prices on general gear, but it's worth the look around just for the fun of seeing racks of hundreds of earbuds and headphones, and all the camera gear (!) etc, etc.
https://goo.gl/maps/rsmZfyTU5Zj7fJmGAhttps://www.yodobashi.com/TsukumoA very well stocked and reasonably priced PC parts store.
They have a number of branches, but I'll link to just the main ones below. Worth a look if you have any interest in PC parts, VR gear, etc.
Main Branch -
https://goo.gl/maps/XXTBJYkD4N6bWhE16Tsukumo eX -
https://goo.gl/maps/RzUXCnSayMWqYdHx9https://shop.tsukumo.co.jp/AisanIf you need electrical installation gear (cable ties, switches, power outlets, etc), conduit, mains cables, PDU's, optic fiber gear, LAN cables, and practically anything to wire and cable an electrical, LAN, or optic fiber installation or data rack etc (Including the rack itself), this is the place to visit.
https://goo.gl/maps/gkBF4kGdPZr3AzQg6https://www.aisan.co.jp/