To provide a cover for a proximity sensor capable of reducing malfunctions due to the difference between a state that a container is placed over an upper part of a proximity sensor by weight of the container and a state the container keeps off the upper part of the proximity sensor when the container becomes empty in the proximity sensor for detecting the remaining amount of the contents along the neighborhood of an outlet of a fluid supply device for taking out the contents from the outlet provided under a flexible, non-self standing container by suction.

The cover for the proximity sensor for detecting the remaining amount of the contents is disposed on the fluid supply device for taking out the contents from the outlet provided under the flexible container by suction and is constituted of a slant surface at a surface including the farthest edge of the proximity sensor from an inlet. Preferably, the cover for proximity sensor is placed over the surface of the proximity sensor, and its top part which is the highest part is located in the neighborhood of the central plumb line of the surface of the proximity sensor.