Provision of a robot which has a simpler configuration and is capable of a stand-up operation. A posture controlling section (10) changes a posture of a robot 1 from a sitting posture to a bridge posture. In the bridge posture, a projected point (T), which represents a center of gravity of the robot (1) projected onto a plane parallel to a support polygon (R) of the robot (1), is at a position that is outside the support polygon (R) and near a right leg part 6 and a left leg part 7.