The present invention concerns an apparatus for automatic processing at least one biological sample accommodated on a carrier member, such as a slide by applying a predetermined amount of reagents in a predetermined sequence according to a processing protocol, said apparatus comprising; a housing frame; at least one processing section for accommodating at least one slide, the at least one processing section is provided within the housing; a hood cover protecting the at least one processing section in said housing; wherein the hood cover completely encloses the processing section defining an interior space; and wherein the apparatus further comprises climate control device provided to control the environment within the interior space.