To provide an apparatus for preparing a hot melt adhesive, adapted so that the desirable features of compactness in designing may be improved, and the easiness of periodical works such as maintenance, repair and/or cleaning may also be improved.

This apparatus for preparing a hot melt adhesive, used for the subsequent application of a hot melt adhesive to a base is composed of at least two opening components (30-40) secured to a common base 20; a housing 50 being a housing 50 secured to the base 20 and enclosing the operating components 30-40 and containing a mobile housing part 54 which reciprocates in a horizontal plane in relation to at least either the base 20 or the housing 50 between the position where the housing is closed to hide the operating components and the position where at least one of the operating components (30-40) is partly exposed and a motion guiding device 60 in which the mobile housing part 54, the base 20 and one remaining housing 50 are operationally connected to each other to move the mobile housing part 54.