THROTTLE BODY STRUCTURE

PROBLEM TO BE SOLVED: To improve a degree of freedom in arranging components to be arranged outside a throttle body.SOLUTION: A throttle body structure has: plural throttle bores 16a, 16b; an idle air control valve provided between the throttle bores 16a, 16b; plural bypass passages extending on a downstream side of the throttle bores 16a, 16b; and bypass ports 44a, 44b arranged between the throttle bores 16a, 16b and supplying idle air to the throttle bores isolated from the idle air control valve. Composite bypass passages 59a, 59b and third bypass passages 52a, 52b are arranged in parallel to each other. The third bypass passages 52a, 52b are communicated with the throttle bores 16a, 16b adjacent to the idle air control valve, and the composite bypass passages 59a, 59b are communicated with the bypass ports 44a, 44b.