A construction machine includes a condenser 24 for cooling refrigerant for an air conditioner; a fan 21 for cooling the condenser 24 by using forward cooling air produced during normal-rotation drive; other cooled objects such as a radiator 25 and the like disposed under the lee of the forward cooling air with respect to the condenser 24; a refrigerant pressure detector 27 for detecting the pressure of the refrigerant flowing in the condenser 24; and a controller 136 for executing reverse-rotation stop processing for returning the fan 21 to the normal-rotation drive when the pressure P of the air conditioner refrigerant detected by the refrigerant pressure detector 27 reaches a preset normal-rotation return pressure P1 during reverse-rotation drive of the fan 21. Thus, the lowering of the cooling effect of an air conditioner can be suppressed while reducing the burden of cleaning an engine room.