The invention relates to a housing module (1) for a brake booster comprising a housing half-shell (3) for housing a moving wall (4), which subdivides an interior space of the brake booster into a low-pressure chamber (5) and into a working chamber (6), and for housing a control housing (11), inside of which a control valve (10) is situated. Said control valve controls a pressure difference that acts upon the moving wall (4), can be actuated by means of an actuating rod (9), and is comprised of two sealing seats (12, 13), which are arranged concentric to one another, and of an elastically deformable valve body (14). The invention is characterized in that the housing half-shell (3) is comprised of a number of parts consisting of at least one metal housing part (15) and of at least one plastic housing part (16).