The invention relates to a gravity cup for a paint spray gun, comprising a reservoir (1) and a lid (2) that is placed thereon and that has a connecting part (3) so that the gravity cup can be placed on the paint spray gun or an adapter. The reservoir (1) is provided, in a wall (4) thereof, with a ventilation hole (6) that can be obturated by means of a valve (5). The aim of the invention is to provide a gravity cup that comprises a valve that can be easily actuated by hand so as to obturate the ventilation hole. For this purpose, the valve (5) is configured as a sliding valve comprising a valve housing (7) and a slide (8) that can be displaced in relation to the valve housing (7) in a direction of displacement (V) extending parallel to the wall (4).