To provide a simplified seat which has good appearance and is accepted even by women and which makes smooth all the movements from a standing posture to a seating posture and has great availability.

A separable container is used as a body in such a way that an upper and a lower container overlap each other. The upper-side container is provided with a stretching band, and its front edge side is attached to a waist belt by connectors which can move freely. A stopper device for fixing the overlapping of the upper and lower containers is also provided in the body.