To instantaneously heat the surface of a toilet seat when a toilet stool is used and to save power by arranging the toilet seat along an opening peripheral edge of the toilet seat on the toilet stool side, providing a seat cover for closing opening of the toilet seat on the toilet stool side with a luminescence part and heating the surface of the toilet seat by radiation heat when light is emitted in this luminescence part.

When a seat cover 25 is in a state that opening of a toilet seat 11 on a toilet stool side is closed, a luminescence part 30 disposed on the toilet cover 25 side faces the surface of a toilet seat 22. When a manual operation switch is operated by pushing the seat cover 25 in a closed state into the toilet seat 22 side before a user is seated on the toilet seat 22 in this state, a luminescence part 30 is turned on and light is emitted in the luminescence part 30 by applying high voltage to the luminescence part 30. By the light emission, the surface of the toilet seat 22 opposed to the luminescence part 30 across a thin and long window 26 is instantaneously heated up to a proper temperature by radiation heat at the time of luminescence. Subsequently, when the seat cover 25 is opened and the user sits on the toilet seat 22, the user can be seated without feeling coldness at this time.