Abstract: An apparatus for assembling a shadow mask and panel of a picture tube of a television receiver, said mask and panel being provided with fixing members engaging each other in a fixed relative position of the mask and panel. The apparatus is provided with separate supports for the mask and panel, one of said supports being made as a floating plate movable relative to the other fixed support parallel to its plane and also perpendicularly to said plane and, in addition, rotatable around an axis perpendicular to said plane. The floating plate is connected to mechanical means for moving the plate relative to the fixed support. In this way, the mask and panel may be positioned only roughly in register on the apparatus, whereby mechanical moving of the floating plate brings the mask and panel in such a relative position that their fixing members automatically engage each other.