In a balance exercise machine (1), a swing mechanism (3) that swings a seat (2) in both of an anteroposterior direction (direction X) and a widthwise direction (direction Y) is rotatably supported on a supporting unit (119 around a predetermined rotation axis (T0). A first inclination mechanism (12) that stands up or down the rotation axis (T0) is provided between the supporting unit (11) and a pedestal (4). A second inclination mechanism (20) that can compensate the posture of the seat (2) is provided between the seat (2) and the swing mechanism (3). By driving the swing mechanism (3), the first inclination mechanism (12) and the second inclination mechanism (20) independently with each other, a stroke of swing motion of the seat can be expanded or contracted. Alternatively, by driving the swing mechanism (3), the first inclination mechanism (12) and the second inclination mechanism (20) in conjunction with each other, the trace of the motion of the seat (2) can be varied.