To provide a semi-autonomous travel type mobile robot, autonomously following up a predetermined trajectory while traveling at a translational speed designated by an operator.

A predetermined trajectory is set and stored in advance in the mobile robot 200. A speed command generating part calculates a translational speed command value Vcmd input by the operator. A self-position estimating part estimates the self-position. A turning speed calculating part obtains a speed ratio of the translational speed for follow-up to the turning speed on a point on the trajectory corresponding to the estimated self-position according to the trajectory expression, and calculates a turning speed command value ωcmd by multiplying the translational speed command value Vcmd by the speed ratio. The mobile robot travels based on the translational speed command value Vcmd and the turning speed command value ωcmd.