A working machine (1) includes a working device (4); a hydraulic system (5) including an actuator (50a, 50b, 50c), and a hydraulic pump (51) to supply a hydraulic fluid (S) to the actuator (50a, 50b, 50c); an electric device (6a, 6b, 6c); a power generator (7) to generate electric power to be directly or indirectly supplied to the electric device (6a, 6b, 6c); a first cooling system (10) to cool the electric device (6a, 6b, 6c) with a first cooling medium (A); and a second cooling system (11) to cool the power generator (7) with a second cooling medium (B). The first cooling system (10) includes a first heat exchanger (100a) to cool the hydraulic fluid (S) through heat exchange with the first cooling medium (A), a second heat exchanger (100b) to cool the second cooling medium (B) through heat exchange with the first cooling medium (A), and a third heat exchanger (100c) to cool the first cooling medium (A) through heat exchange with outside air to a temperature lower than temperatures before the heat exchange of the hydraulic fluid (S) and the second cooling medium (B).