PROBLEM TO BE SOLVED: To perform the movement of a mobile robot so that interference between a movable link and a structure can be avoided when the mobile robot is made to lift up and down the structure such as a ladder and a step ladder.SOLUTION: A control device 40 of a mobile robot 1 estimates a deviation between an actual position attitude at a tip section 13 of a support object movable link 3 supported by a structure A and a target position attitude in a lifting up/down operation of the mobile robot 1. The control device further determines an operation target of the mobile robot 1 so that at least one of a target position/attitude relative to a base body 2 at the tip section 13 of the support object movable link 3 and a target support position/attitude at the tip section 13 of a moving object movable link 3 to be separated from the structure A and moved is adjusted according to the estimation value of the support position attitude deviation.SELECTED DRAWING: Figure 4
