Abstract: An apparatus for illumination having a housing suited for in ground use, which contains at least one lamp which is surrounded by a reflector, has a light changer, and a controller for controlling at least the lamp and the light changing means. To reduce the content of moisture air containing evaporated water is able to be released from the lamp to the surroundings and only air without moisture is allowed to enter the in-ground lamp. This can be achieved with a housing with an outer casing which has at least one diaphragm covering at least one downwardly directed opening which is open towards the surrounding environment, the diaphragm being permeable for moisture for transmission from the inside of the housing to the outside, but is water-tight inward from the outside. Even in a situation where the apparatus is completely overflowed, the diaphragm prevents water penetrating from the outside.