AIR-CONDITIONING DEVICE FOR VEHICLE

Provided is an air-conditioning device (10) for a vehicle, including: a cooling device (16) configured to cool air passing through a duct (12); a heater core (18), which is arranged in the duct on a downstream side of airflow with respect to the cooling device, and is configured to use an engine coolant as a heat source to heat the air; a water valve (22) provided in a coolant circulation system (26) on an upstream side of the heater core; and a control device configured to control those components, in which the control device is configured to decrease an opening amount of the water valve in a predetermined cooling mode. The control device is configured to, when the opening amount of the water valve is decreased, decrease a rotational speed of a compressor (50) of the cooling device, and increase a target evaporator temperature of an evaporator of the cooling device, thereby decreasing cooling performance of the cooling device.