Abstract: The present innovation pertains to a device with which containers, in which water collects in an unintentional manner, are automatically drained. An outer housing (2, 3), which can be inserted into the bottom of the container, is subdivided by a web (8a) into two chambers, one of which is connected to the interior of the container, and the other of which is connected to the surroundings of the container. The web encloses an opening (20) which connects the two chambers when a valve member (14) has moved away from a seat (8b) enclosing the opening. If the valve member rests on the seat, the chambers are separated from one another, and the interior space of the container is not in connection with the surroundings of the container. The movement of the valve member is controlled by the water level in the chamber which is in connection with the interior space of the container.