To enable use of a step motor having no moistureproofness as a drive source for a diffuser side movable louver in a bathroom and realize a motor-driven louver at a low cost.

A bathroom drier 1 has a circulation fan block 5 and a heat exchanger 4 housed in a main body 15 installed in a ceiling of the bathroom and the movable louver 6 provided at a diffuser side 5b of the circulation fan block 5. A louver-driving motor 7 for driving the movable louver 6 is housed in a motor installation space 8 shut off from a bathroom space 3 and the motor installation space 8 is permitted to communicate with an attic space 9 of the bathroom 2.