To realize a traveling robot capable of maintaining the state where a driving wheel is grounded even the robot travels on an undulating ground.

The traveling robot is equipped with a driving wheel 38, driven wheels 56 which are disposed in front of and at the rear of the driving wheel 38 respectively, a mechanism 50 which vertically movably supports the driven wheels 56, and a means 70 energizing the driven wheel 56 toward the ground. When the traveling robot travels on the undulating ground, and the driving wheel 38 and the driven wheels 56 pass on the ground having different height, the support mechanism 50 and the energizing means 70 are operated to move the driven wheels 56, and maintain the state where the driving wheel 38 is grounded.