Provided is a construction machine in which a reduction agent hose is less likely to be influenced by heat and the reduction agent hose can be routed by efficient use of a limited space above a rotarybody including an engine room. According to the present invention, a reduction agent tank (11) is disposed in a first space (SP1) upstream of a heat exchanger (21) in a cooling air flowing direction,and an engine (13) and an injector (14) are disposed in a second space (SP2) downstream of the heat exchanger (21) in the cooling air flowing direction. The heat exchanger is placed on a bracket (30)having a first lateral plate part (32), a second lateral plate part (33), and a top plate part (31). A first cutout portion (34) through which a reduction agent hose (25) is inserted is provided in the first lateral plate part, and a second cutout portion (35) through which the reduction agent hose is inserted is provided in the second lateral plate part. A part of the reduction agent hose is passed through the first cutout portion and the second cutout portion so as to be routed in the inner space (SP3) of the bracket.