To provide a mobile robot capable of exhibiting excellent high-speed traveling performance on a leveled ground as well as excellent traveling performance on an unleveled ground, moreover, capable of jumping over an obstacle with an overhang.

This mobile robot includes a vehicle body 2 and legs 3 located at four positions of front, rear, left and right of the vehicle body 2. The legs 3 has a first wheel 4A and a second wheel 4B which include a driving mechanism 4b for reversely turning a vehicle wheel body 4a so that it can be secured in an appropriate position, and a mode switching mechanism 10 for appropriately allowing either of the two wheels 4 for the legs 3 to be in contact with the ground in accordance with a driving mode of running on a paved or rough road, moreover, horizontally turning either of the two wheels 4 in a jumping-over obstacle mode.