To provide a standing assistance device and a wheelchair to which the same is attached, with which it is possible to safely provide assistance in a standing operation and a seating operation without allowing a user to slip out of a seat. A standing assistance device 10 comprises: a body frame 16 that is removably installed on a seat surface 14 with engaging parts 34, 48 interposed therebetween； a seat 18 provided on the body frame 16, a front seat part 60 and a rear seat part 62 being coupled by a hinge 22, and the front end of the front seat part 60 being supported by the front end of the body frame 16 so as to be capable of rotating upward and downward； a seat movement mechanism 20 that causes the seat 18 to rotate upward and downward by imparting rotational force at the center of the lower surface of the rear seat part 62, thereby causing the seat 18 to move between a seating position and an upright position； an anti-reverse-rotation member 24 that prevents the seat 18 from rotating in reverse； and a rear-seat-part forward-inclination adjustment means 26 that adjusts the degree of forward inclination of the rear seat part 62 when the seat 18 is rotated from the seating position to the upright position.本發明提供一種起立輔助裝置，其係可使使用者不會從座部滑落而能安全地支援起立動作及坐下動作。本發明並提供一種安裝該起立輔助裝置之輪椅。本發明之起立輔助裝置10，具備：本體框架16、座部18、座部移動機構20、逆彎防止零件24、後座部前傾調整手段26；本體框架16，係介由接合部34、48可自由裝卸地載置在座面框架14上；座部18，係設置於本體框架16上，前座部60及後座部62以鉸鏈22連結，且前座部60之前端部於本體框架16之前端部可上下自由轉動而支撐；座部移動機構20，係藉由在後座部62之下面中央賦予轉動力而上下轉動座部18，使座部18在坐下位置與站起位置之間移動；逆彎防止零件24，係防止座部18逆彎；後座部前傾調整手段26，係座部18從坐下位置轉動至站起位置時，調整後座部62之前傾角度。
