A robot is obtained having various functions that are demanded for planetary landing vehicles, extreme operations robots or the like, in particular to provide a leg structure for a robot that is capable of getting up itself when overturned, facilitating take-off and landing on uneven ground, and that has a walking function and that has a hand function capable of three-dimensional operation. A robot comprises a main robot body and at least three legs mounted on this main body for enabling three-dimensional movement of the main robot body such as a self-erecting action or walking action; each leg is constituted by a multi-joint arm having a plurality of said offset rotary joints linked together and has a ground-engaging member mounted at the leading end of the arm, so that each leg is capable of independently controlled three-dimensional movement and drive.