A power conversion apparatus comprising a base which includes a first fixation portion and a second fixation portion that are coupled to each other at a desired angle, wherein power modules are fixed on the first fixation portion of the base, a control circuit board is fixed with its first principal surface held in direct or indirect touch with the second fixation portion of the base, and components constituting a control circuit are packaged on the second principal surface of the control circuit board. Owing to the configuration, a versatility for the installation of the power conversion apparatus on a vehicle becomes high, the vibration-proofness of the control circuit board is enhanced, and heats generated by the electronic components, etc. packaged on the control circuit board are sufficiently emitted.