An assistance apparatus includes a first wire and a second wire that couple an upper-body belt and a left knee belt to each other on or above a front part and back part of the body of a user, respectively, a third wire and a fourth wire that couple the upper-body belt and a right knee belt to each other on or above the front part and back part of the body of the user, respectively, a motor, a left sensor on the left hand of the user, and a right sensor on the right hand of the user. When a force is applied to the left sensor and no force is applied to the right sensor, the motor makes the tension of the second wire and the third wire greater than the tension of the first wire and the fourth wire. When a force is applied to the right sensor and no force is applied to the left sensor, the motor makes the tension of the first wire and the fourth wire greater than the tension of the second wire and the third wire.