PROBLEM TO BE SOLVED: To provide a chair cushion for holding a seated user in an appropriate posture and dispersing a pressure without giving discomfort to the user, and capable of suppressing the occurrence of pressure sore.SOLUTION: A chair cushion secures an appropriate seating posture by: arranging a base part 13 for supporting a pressure receiving part 10 together with the pressure receiving part 10 where many air cells expanding and contracting by supplying/exhausting air are arranged； arranging a supply/exhaust control part 14 in the front center of the base part 13； including a front support part 15 arranged above the base part 13 while covering the supply/exhaust control part 14 so as to support the hip of a seated user by the air cells of the pressure receiving part 10, sharing with each other； and on the other hand, supporting the thigh by the front side support part 15 so as to support the hip with good balance as the whole while the air cells change the shape by being pushed by the hip. Furthermore, in the front side support part 15, the thigh is supported on right and left two places respectively, out of a central part having the supply/exhaust control part 14 so as to bring no discomfort to the user, and disperse a body pressure by the whole cushion to cause no pressure sore brought by seating.
