least one of the individual suction pipes 11 the swirl control valves 15 and the fuel injection valves 91 are provided on the collector 10 serving as a negative pressure chamber downstream of the throttle valve 8 while the suction air quantity detecting means 7 is located upstream of the throttle valve 8 in this preferred embodiment the detecting means 7 may be located downstream of the throttle valve 8 the throttle valve 8 is mounted on a member a portion below the line a a in fig2 b forming the suction ports 4 respectively communicating with suction ports 17 formed in the engine 20 a second preferred embodiment of the present invention is shown in fig3 in this preferred embodiment the individual suction pipes 11 and the suction ports 4 communicating with the suction ports 17 of the engine 20 are formed in a single member a portion below the line a a in fig3 and the throttle valve 8 is mounted to this member a third preferred embodiment of the present invention is shown in fig4 in this preferred embodiment the collector 10 is formed just above the individual suction pipes 11 the air passing through the throttle valve 8 is first raised to the collector 10 and.