Visitors have an unpronounced expectation of the cleanness in a museum. Especially the art objects must be clean and well-kept. The organisation of cleaning requires a five-phase plan: drawing up standards; listing of wishes; setting up a program and calculating costs; assignment of tasks; training; introduction of a quality measuring system. Standards and wishes must be defined strictly and precisely by the museum; not doing so will result in irresponsible methods of cleaning. The special circumstances and wishes in a museum may lead to a relatively high price, in comparison with an average office building. When specific tasks are assigned to specific persons it should be known who is responsible and what has to be done in case of unforeseen absence. Effective cleaning can only be done by trained personnel. Quality measurement is necessary in order to maintain a high level of qualified personnel and a sound planning.