The invention relates to a manipulator arm for an apparatus, having a head which can be aligned with a region to be observed or to be blasted. The manipulator arm (2) is equipped with an end piece which carries a head (25) in a manner swivelable by motor and has in the region of the head at least two adjacent proximity sensors (58, 59) which are directed at the surface and connected to a control circuit which controls the drive of the swivel motor for the head. <IMAGE>
