To use a legless chair pleasantly in variety of use mode.

This chair is provided with a seat part 1 and a back rest part 2 being rotatable in the front and back direction through a switching mechanism 5 and freely lockably supported on a shaft at plural stages at required angles at the back end of this seat part 1. A multipurposely usable arch-shaped part 4 which can be used as a backrest, a pillow, etc., is supported on the shaft freely rotatably in the up and down direction, at a desired angle, at plural stages and freely lockably at the front end part of arm rest parts 3 and 3 stood on both left and right sides of the seat part 1 through the switching mechanism 5 and is constituted by extending it forward.