An air conditioner for a vehicle having a passenger compartment has an electric-powered hot water pump in addition to a mechanical hot water pump driven by an engine mounted on the vehicle. The electric-powered hot water pump is activated while the engine is stopped. However, the electric-powered hot water pump is kept in a non-activation state while an air mix door is positioned in a low temperature side as compared to a predetermined value and an elapsed time after the engine is stopped is within a predetermined time so that power consumption by the electric-powered hot water pump can be decreased suitable for a hybrid vehicle having a driving motor in addition to the engine.