A bipedal robot has an upper body that includes a higher upper body and a lower upper body. The higher upper body and the lower upper body are coupled to each other by a rotating mechanism so as to be rotatable with respect to each other about a vertical axis of rotation. Two legs extend from the lower upper body, and two arms extend from respective shoulders on opposite sides of the higher upper body. The higher upper body of the robot has a thickness in a forward/rearward direction and the lower upper body has a width in a lateral direction, the thickness and the width being smaller than the width in a lateral direction of the robot at the shoulders. An electric energy storage device, which serves as a power supply for operating the robot is mounted in the higher upper body, and an electronic circuit unit for controlling operation of the robot are mounted in the lower upper body. With this robot arrangement, the robot is capable of increased working capability without impairing the stability of the attitude when the robot works.