Abstract: A working machine may include: a fan configured to generate an air flow inside a first space; a control unit disposed inside the first space; a partition wall separating the first space from a second space; a first aperture communicating the first space with the second space; and a rib extending from the partition wall and forming an air passage in which the air flow passes, wherein the air passage is positioned between the control unit and the rib. The control unit may include a case housing a circuit board. The control unit may include a first surface facing the rib. In a first direction perpendicular to the first surface, the rib and the first surface may at least partially overlap with each other. A distance between the rib and the first surface may be smaller than a thickness of the case in the first direction.