The invention relates to a treatment apparatus (1) for treating a surface (21) of a body (2) with a first treatment medium (31) and a second treatment medium (32). In this respect, the treatment apparatus (1) includes a holding device (5) rotatable about an axis of rotation (4) for receiving and holding the body (2) and a rotary drive (6) rotationally fixedly coupled to the rotatable holding device (5) as well as a supply device (7) for supplying the first treatment medium (31) and the second treatment medium (32) to the surface (21) of the body (2) held in the holding device (5). The treatment apparatus includes a collection container (8) having a separation element (80) which separation element (80) divides the collection container (8) into a first chamber (81) and into a second chamber (82) such that the first treatment medium (31) can be collected in the first chamber (81) and the second treatment medium (32) can be collected separately in the second chamber (82). In accordance with the invention, the collection container (8) includes a base chamber part (800) not movable with respect to the holding device (5) and the separation element (80) is movably arranged between a first position (A) and a second position (B) such that the first treatment medium (31) can be led off into the first chamber (81) in the first position (A) and the second treatment medium (32) can be led off into the second chamber (82) in the second position (B).