Intake manifold

An intake manifold is provided that comprises a plurality of intake ducts, a surge tank, a vacuum chamber, and a negative pressure check valve. The negative pressure check valve enables negative pressure induced in the surge tank to flow into the vacuum chamber. Each upstream end of the intake ducts protrudes into the inside of the surge tank. Further, a pressure inlet formed inside the surge tank, to lead the negative pressure induced inside the surge tank to the negative pressure check valve, is positioned on a side closer to an engine than the respective upstream ends of the intake ducts.