A valve body unit (11) in which a plurality of valve bodies (17) which open and close intake passages (10) are attached on a rotational shaft (16) is inserted into inner sides of housing passages (28) of a housing (12) and, thereafter, a holder (13) is mounted in the housing (12) to rotatably support the valve body unit (11). A flange (14) is fixed onto an upper surface of the housing (12) on the holder (13) by means of a vibration welding and the holder (13) is retained with this flange (14) and the housing (12).
