To easily attach or detach a partition plate by providing a partition chamber partitioned by the plate in a cold storage chamber.

The lower part of a cold storage chamber 12 is vertically partitioned by a ceiling plate 15 to partition of form a chilled chamber 16. A bead part 31 is provided in the inner sidewall of the chamber 12 and rear half part of both right and left sides of the plate 15 is sandwiched and supported. A rib-like part to be locked is provided in the lower surface of the front end of the plate 15, while a recess for locking the part to be locked to a position control state of a longitudinal direction is provided at a side plate of the chamber 16. The front end of the plate 15 is slightly raised upward to release the locking state by the recess. Then, the plate 15 is drawn forward, and drawn out from the bead part 31, and hence the plate 15 can be removed.