This is an old Imari-ware, sometsuke (blue and white) mukouzuke (small serving dish), also usable as a sobachoko (soba noodle cup). Perhaps it's a tsutsu-mukouzuke (cylindrical serving dish)? It can be used as a sobachoko, and it's a wonderful piece that can be used for various purposes. I've kept it carefully in its box for many years, but I've decided to sell the complete pieces separately from those that aren't. Both of these are complete, and I think they have a very rare and wonderful atmosphere. Approximately 9.3cm in diameter x 6.5cm in height.