Dirt is caused by people, but people are also the ones who remove dirt. This booklet has been written in order to foster a good influence on the behaviour of both these types of people. It is the intention that every page is read whilst keeping in mind, how do these people behave in these buildings, and what is behind it all? Even though much has already been written about cleaning, and right from the beginning of our existence we have been occupied with it, it does seem necessary to explain about cleaning in museums, record offices and historic buildings. The first few chapters give explanation of general remarks and ideas about cleaning, whilst in the following chapters more detailed information is given about the actual cleaning of areas and ensuing matters that need to be given careful consideration. This publication gives information about the general priorities when cleaning; the details of the work in hand have to be worked out in relation to the relevant building.