To easily generate a defecation desire by forming the inner peripheral side of a toilet seat steeply tilting down into the stool so as to naturally open an anus when sitting on the toilet seat.

Then outer peripheral side 2 of a toilet seat 1 is formed flat, the inner peripheral side of the seat 1 is formed in the shape of steeply tilting down toward the inside of the stool 1 on the other hand and the edge 4 of the inner periphery is pulled back from a steep tilt to a gentle flat surface. In addition, the outer peripheral side 2 can be curved toward the outside of the stool 7 to a side opposite to the inner peripheral side 3 to form the inner/ outer periphery in the shape of a reverse U at a cross section part depending on a case. Or, a form lowering straight from the side 2 to the side 3 like a mortar can be used. At the time of using, a user places his hips on the side 3 lowered by steep tilt and sits down on the seat 1 so as to open his legs. His anus is widely opened at this time to stimulate his rectum to easily generate a defection desire.