POWER CONVERSION DEVICE

A power conversion device comprises a power conversion circuit, and a multilayer substrate that includes the power conversion circuit, and has a wiring pattern. The wiring pattern of the multilayer substrate includes a power supply pattern, and a ground pattern. The multilayer substrate includes a first layer and a second layer. The power supply pattern includes a first layer power supply pattern portion in the first layer. The ground pattern includes a second layer ground pattern portion in the second layer. The first layer power supply pattern portion and the second layer ground pattern portion overlap with each other at least in part in a direction perpendicular to a plate surface of the multilayer substrate.