To provide a control device for an air conditioner for a vehicle that can control the generation of liquid compression sound within a compressor at the time of use of a vehicle by the liquid-compression actuation of the compressor at the time when the vehicle is not used, thus can eliminate transfer of the liquid compression sound to a passenger.

The control device is provided with a starter 2, the compressor 31, and a control means 4. The starter starts an engine 1 mounted on the vehicle, and the compressor constitutes a refrigeration cycle of the air conditioner and is driven by the engine 1. Then the control means actuates the starter 2 and the compressor 31. The control means 4 starts the starter 2 when it estimates that a refrigerant for the air conditioner is liquefied within the compressor 31 at the time when the vehicle is not used.