To provide a foot warmer which gets energized and warm when the foot is placed on the foot plate and is de-energized when the foot is removed from the plate to leave the foot warmer.

When a mounting base 2 is pushed down against a spring 12 when a user places his feet on the mounting base 2 and a switch 5 is closed because an operating piece 7 at the inside operates by interlocking with the push-down, a heater is energized and the surrounding of the mounting base 12 on which the feet are placed is warmed. When the feet are put off from the mounting base 12 in the state, the mounting base 2 is pushed up by spring force and the switch 5 is opened and the heater is not energized because the operating piece 7 interlocks with an upper side.