An object of the invention is to provide a power converter that can be reduced in size. To achieve this, a power converter according to the invention includes: water passages arranged radially from an assumed central axis, each being trapezoid-shaped in cross section; and power modules placed between the water passages such that each of the power modules is sandwiched from both surfaces thereof by the water passages. Each of the power modules has an output terminal and positive and negative terminals on an end face located in a centrifugal direction side with respect to the assumed central axis. Any of the power modules and an adjacent one of the power modules are set in a front-back inverted manner.