PURPOSE: To provide the car door device of a dumbwaiter which can completely prevent an accident due to sticking out of cargo during ascent and descent of a car by closing cargo in/out port of the car completely irrespective of size of a top clearance.

CONSTITUTION: A car door device of dumbwaiter is provided with a folding type car door 12 which is attached to a cargo in/out port of a car 1 and opened and closed by expanding and shrinking while sliding in the up and down directions guide rails 13 on the right and left which are erected on both right and left sides of the cargo in/out port and guide the folding type car door 12, and a door pocket frame 14 which is provided vertically in a lower end section of the cargo in/out port along the guide rails 13 on the right and left in such a way that it can ascend and descend freely and stores the folding type car door 12.