To detect lateral dislocations of workpieces precisely by employing fine control whereby hands are translated sideways with their orientation kept unchanged through simple control.

For translating a hand H sideways with its orientation unchanged, lateral movement control part C1 within a robot controller C rotates a pivot 2 and a wrist shaft 4 by the same angle in the opposite directions while checking the rotation of a second shaft 3 to thus move the hand H about the pivot 2 as in wipers.