POWER SUPPLY DEVICE

A power supply device () for a seat that can slidably move relative to a rail () that is provided in the floor portion () of an automotive body, the power supply device () including: the power transmission unit () that is provided in the floor portion (); the rotation shaft portion () that is fixed to the seat, and serves as the rotation axis of the seat; and the power reception unit () that is fixed to the rotation shaft portion () and is configured to receive power from the power transmission unit ().