19. A power converter mounted on an electric vehicle comprising:a power module configured to convert electrical power when the electric vehicle is driven;
a low-heat-generating electrical device configured such that amount of heat generated during operation is smaller than amount of heat generated by the power module;
a case configured to have a mounting portion on which the power module and the low-heat-generating electrical device are mounted; and
a cooling-medium flow channel structured to permit cooling medium to flow through the cooling-medium flow channel, the cooling-medium flow channel being formed in the mounting portion, wherein
the low-heat-generating electrical device includes at least one of a capacitor module, a charger, or a DC/DC converter, and
the cooling-medium flow channel is configured such that a portion for cooling the low-heat-generating electrical device has a larger flow-channel cross-sectional area than a portion for cooling the power module, the low-heat-generating electrical device being configured to be cooled by the cooling medium after the power module is cooled.