In a legged mobile robot having a body and legs connected to the body, a seating aid is provided at its body so as to enable to sit on a seat. With this, the space occupied by the robot can be decreased to reduce space during storage and transport, and also enhance safety in the course of transport. In addition, maintenance work is simplified because immobilization in the seated condition is possible. Still further, the range of works is expanded to enable deskwork and the like. Further, the seating aid is provided at a location that is rearward of a center of gravity of the robot when the robot is seated. With this, the moment acting on the robot about the center of gravity during seating does not operate to tilt the robot rearward and, therefore, the robot can be enabled to keep a stable posture from before to after sitting down.