A construction machine includes: a cover that covers an engine and a radiator; a radiator fan that is arranged at the rear of a vehicle body frame and discharges exhaust gas toward the rear of the vehicle body frame from the inner space of the cover; an injection device that injects a reducing agent into exhaust gas of the engine; a tank housing section that is arranged at one side of the vehicle body frame, includes an introduction section for introducing outside air, and houses a tank for storing the reducing agent injected by the injection device; and a connection section that is arranged in either the cover or the vehicle body frame and in the tank housing section, connects the inner space of the tank housing section and the inner space of the cover, and allows the outside air and the pipe to pass therethrough, the outside air having been introduced from the introduction section by the suction pressure of the radiator fan, the pipe supplying the reducing agent to the injection device.