A power conversion apparatus includes: a converter main circuit converting AC power into DC power; an inverter main circuit converting, into AC power, the DC power obtained by conversion by the converter main circuit; and a common cooler cooling first switching elements included in the inverter main circuit and second switching elements included in the converter main circuit. The first switching elements are modularized in units of one or more elements to form first modules. The second switching elements are modularized in units of one or more elements to form second modules. The first and second modules are mounted on a first surface of a base of the cooler. The first modules are arranged in a first direction on the first surface. The second modules are arranged such that two or more second modules are continuously arranged in a second direction orthogonal to the first direction on the first surface.