A power conversion device includes a semiconductor module, a cooling device, a case, which accommodates the semiconductor module and the cooling device, a connector, which is connected to an inlet pipe, which is a refrigerant flow pipe of the cooling device, and a sealing member, which seals between the inlet pipe and the connector. The connector includes a pipe portion, which communicates with the inlet pipe, and a flange portion, which is secured to the case. The pipe portion and the flange portion are joined to each other with the pipe portion located in an insertion hole of the flange portion.