To provide a legless chair capable of effectively preventing slippage on a seat plate part and slippage on a floor to enable a seated person to always keep on sitting in a repose posture.

This legless chair 30 is formed by a legless chair body 10 made by molded plywood (bent plywood) having a seat plate part 1 having a round lightening hole 1a in the central part and a backrest part 2 integrally raised on the rear part of the seat plate part 1, and a cushion 20 for the legless chair, having a wooden round male plate 22 fitted in the lightening hole 1a of the seat plate part 1 on the lower surface. The male plate 22 on the lower surface is engaged with the lightening hole 1a of the seat plate part 1 to surely prevent the cushion 20 from slipping on the seat plate part 1.