This dehumidifying device comprises an operation control unit configured so as to switch between thermo-on for circulating a refrigerant in a refrigerant circuit and thermo-off for stopping refrigerant circulation and an operation mode control unit configured so as to switch between a first operation mode for causing a moisture-adsorbing means to adsorb moisture and a second operation mode for desorbing the moisture held in the moisture-adsorbing means. According to the operation mode and the relative humidity of the air when switching from thermo-on to thermo-off, the operation mode control unit selects the operation mode to be used when thermo-on is operated after the thermo-off.
