A power converting apparatus includes a housing base, a main body, an air duct, a pair of upright air duct walls, first and second heat generators, and a protrusion. The housing base has first and second surfaces. The main body is on the first surface. The air duct is for cooling air to flow through the air duct and is on the second surface. The upright air duct walls are on the second surface and extend from an upwind side to a downwind side. The first and second heat generators are disposed in series from the upwind side to the downwind side in the air duct. The protrusion is between the first and second heat generators to protrude from at least one of the pair of air duct walls toward a center portion of an air-flowing space for the cooling air.