PROBLEM TO BE SOLVED: To provide a posture holder capable of holding the posture of a seated person by changing a shape in response to the backs of various seated persons and also keeping the shape.SOLUTION: A posture holder 10 is arranged between a backrest part 4 of a chair 3 on which a seated person 1 is seated and a back surface 2 of the seated person 1, and deformed along the shape of the back surface 2 by the supply of air while the backrest part 4 is inclined or erected. A back surface opposing part 12 opposing to the back surface 2 is brought into contact with the back surface 2, and the backrest part 4 is stopped so as to allow the air to be exhausted, so that the shape of the back surface 2 is kept.SELECTED DRAWING: Figure 3【課題】 様々な着座者の背中に合わせて形状を変化させると共にその形状を維持し、着座者の姿勢を保持することができる姿勢保持具を提供する。【解決手段】 姿勢保持具１０は、着座者１が着座する椅子３の背もたれ部４と着座者１の背面２との間に配置され、背もたれ部４が傾倒または起立しながら給気されることで背面２の形状に沿って変形すると共に、背面２と対面する背面対面部１２が背面２と接触し、背もたれ部４が停止して排気されることで背面２の形状を維持する。【選択図】 図３
