Abstract: An exercise assisting instrument assists the user's knee-bending exercise, and lightens a burden and maintains safety of the user. It has a base 10, supporting columns 20, lifting mechanisms 30 consisting of lifting arms, lever arms 40, and a chair 50. A three-member linkage system is formed by the supporting columns 20 and the lifting mechanisms 30, so that the chair 50 may move upward and downward. Further, it is equipped with an upward movement assisting device 33, which provides a force in the raising direction to the hinge point 30a of the lifting arms, so that stand-up movement of the user is assisted and lightening the user's burden is possible. Moreover, a locking device 11 and a stopper 13 are equipped, so the user's safety may be improved.