A work holding device is intended for use in combination with a processing machine, such as an assembling apparatus, an industrial robot or a machine tool. The work holding device comprises a base plate (8), a slide base (9) supported for vertical movement on the base plate (8), a swivel head (10) supported for turning on the slide base (9), and a rotary table (11) supported on the swivel head for rotation about an axis perpendicular to the axis of turning of the swivel head. The slide base (9), the swivel head (10) and the rotary table (11) are controlled properly to set a work (12) held on the rotary table (11) in an optional position relative to the associated processing machine. The work holding device and the processing machine are controlled for synchronous operation by a single controller according to a control program.