A chair includes: a backrest with a waist support projecting part a horizontal forward seat a backward seat pivotally supported so as to be able to swing downward relative to the forward seat a leg support pivotally supported at a front end of the forward seat links for changing a positional relation between the rear end of the backward seat and the lower end of the backrest so that a distance from the waist support projecting part to the backward seat is reduced from a standing posture to a tilted posture as the backrest is tilted backward and a connection link for connecting the lower end of the backrest and a part of the leg support lower than the upper end of the leg support so as to cause the leg support to swing forward as the backrest is tilted backward.