The name of this shop really doesn't do it justice - more than just a souvenir shop or museum shop, it's actually one of the best design shops in Tokyo. You'll find excellent selections of pottery, glassware, fabrics, paper goods and many other crafts scattered thoughout the store, along with more typical museum-shop goods like artsy postcards, T-shirts and art books.
There's also a good amount of retail space devoted to temporary, individually curated pop-up shops that are here for just two or three months at a time. A recent visit coincided with popup shops devoted to coffee mugs and leather messenger bags, with impressive collections of both.
Display areas throughout the shop are well laid-out, with spacious aisles that don't feel too cramped even during peak weekend-afternoon sales hours. Located just a short walk from Tokyo Midtown, this is one museum shop that's worth checking out even if you're not seeing a show at the attached museum.