When an emergency stop button 12 is pressed after a robot 1 passes a teaching point P.sub.N, and then reach a position P.sub.E, the robot 1 is stopped at a position P.sub.S diverted from the predetermined teaching route L. When the start button is pressed next, the robot 1 moves at a speed V.sub.L lower than a teaching speed V.sub.t until it reaches a next first teaching point P.sub.N+1. Passing first teaching point P.sub.N+1, the robot 1 moves at the teaching speed V.sub.t. The robot 1 moves at the low speed VL at a restarting time, so that an operator can check for interference between the robot 1 and the workpiece W. Passing the next first teaching point P.sub.N+1, the robot 1 moves at the teaching speed V.sub.t, so that the reduction of the operation efficiency can be prevented.