A printing apparatus includes a power-supply unit, a printing unit, a circuit board (main wired board), and a cooling unit. The main-wired-board cooling unit includes: an inflow portion including an inlet from which air outside of a housing flows in, the inflow portion being disposed on a rear surface of the housing; a first flow path in which the air flowing in flows to a front surface side of the housing; a turn-around flow path causing the air flowing in the first flow path to be turned around to a rear surface side of the housing; a second flow path in which the air turned around flows to the rear surface side; a flow-out portion including an outlet from which the air flowing through the second flow path flows out to an outside of the housing, the out portion being disposed at the rear surface; and a fan (main fan) causing the air to flow in from the inlet and also causing the air passing through each of the flow paths to flow out from the outlet. The main wired board is disposed within the second flow path.