To provide a toilet seat that has no operating temperature limit, can automatically be opened under any temperature environment, is easy to use, is stain-resistant, and reduces an exchange frequency.

There are a toilet seat facing a toilet cover and equipped with a first introducing hole and a second introducing hole at both sides, and a plurality of main bodies introduced into the first introducing hole or the second introducing hole formed in hollow structure in the toilet seat. The main body comprises a separating wall that is formed inside and is separating the inside into an upper space and a lower space having a suitable slope angle, a plate allowed to move in a single direction and equipped at a suitable position of the separating wall's one end, a plate equipped at the other end of the separating wall, a spring equipped at the lower part of the latter plate, and a plurality of spheres stored in the main body.