CONSTRUCTION MACHINE

To provide a construction machine capable of improving cooling efficiency of a heat exchanger and reducing noise in a configuration in which a prime mover, a heat exchanger, and an air cleaner for supplying clean air to the prime mover are arranged in an engine room. The excavation work machine comprises an engine room provided on a swivel frame and housing equipment including an engine and a heat exchange unit, a ventilation part provided on a right exterior cover forming a side wall of the engine room and having a plurality of ventilation holes for communicating inside and outside of the engine room, and an air cleaner arranged between the heat exchange unit and the ventilation part in the engine room, and supplying cleaned air to the engine.