A power conversion device according to an embodiment includes an element unit and a capacitor unit. The element unit includes a first positive electrode bus, a first negative electrode bus, and a first outer frame member. The capacitor unit includes a second positive electrode bus, a second negative electrode bus, and a second outer frame member. The first outer frame member and the second outer frame member are separable from each other. The first positive electrode bus and the second positive electrode bus are removably connected to each other. The first negative electrode bus and the second negative electrode bus are removably connected to each other.