A railway vehicle comprising a power conversion apparatus and an air-conditioning apparatus (74, 81), wherein the air-conditioning apparatus (74, 81) is power supplied by the power conversion apparatus, said power conversion apparatus comprising a power converter including a plurality of functional modules (7, 1 to 7, 3) which include two or more of a functional module (7, 1) in which a rectifier unit (15, 1) configured to rectify an alternating-current voltage externally supplied and an inverter unit (11, 1) configured to convert a direct-current voltage into alternating-current power are combined, a functional module (7, 2) in which a converter unit (13, 2) configured to convert an alternating-current voltage into a direct-current voltage and an inverter unit (11, 2) configured to convert a direct-current voltage converted by the converter unit (13, 2) into alternating-current power are combined, and a functional module (7, 3) in which an inverter unit (11, 3, 11, 4) configured to convert a direct-current voltage into alternating-current power is provided, and at least one power conversion unit constituted by a semiconductor component, configured to convert power, and mounted in each of the functional modules (7, 1 to 7, 3), the power conversion apparatus further comprises a cooler configured to contact with the semiconductor component mounted in each of the functional modules (7, 1 to 7, 3) to cool the semiconductor component, and an accommodating section accommodating the power converter and the cooler, wherein the accommodating section includes a closed chamber sealing off the power converter, and an open chamber with an opening through which heat transferred by the cooler is transferred to outside air, wherein the cooler includes a heat receiving section provided on a closed chamber side and receiving heat generated from the at least one of functional modules (7,1 to 7, 3), and a heat radiating section provided on a open chamber side and transferring heat received by the heat receiving section, wherein the heat radiating section includes a plurality of heat radiating fins, and wherein the plurality of heat radiating fins is formed in a same direction as a cooling fan blows air toward the plurality of heat radiating fins, wherein at least one of the functional modules (7, 1 to 7, 3) has two power conversion units in which respective amounts of heat generated are different, wherein one of the two power conversion units in which the amount of heat generated is small is disposed at a position corresponding to a downstream side of the cooler, and wherein the other one of the two power conversion units in which the amount of heat generated is large is disposed at a position corresponding to an upstream side of the cooler. a functional module (7, 1) in which a rectifier unit (15, 1) configured to rectify an alternating-current voltage externally supplied and an inverter unit (11, 1) configured to convert a direct-current voltage into alternating-current power are combined, a functional module (7, 2) in which a converter unit (13, 2) configured to convert an alternating-current voltage into a direct-current voltage and an inverter unit (11, 2) configured to convert a direct-current voltage converted by the converter unit (13, 2) into alternating-current power are combined, and a functional module (7, 3) in which an inverter unit (11, 3, 11, 4) configured to convert a direct-current voltage into alternating-current power is provided, and a cooler configured to contact with the semiconductor component mounted in each of the functional modules (7, 1 to 7, 3) to cool the semiconductor component, and an accommodating section accommodating the power converter and the cooler, a closed chamber sealing off the power converter, and an open chamber with an opening through which heat transferred by the cooler is transferred to outside air, a heat receiving section provided on a closed chamber side and receiving heat generated from the at least one of functional modules (7,1 to 7, 3), and a heat radiating section provided on a open chamber side and transferring heat received by the heat receiving section,