The motorcycle includes: a supercharger that pressurizes intake air to supply the pressurized intake air to an engine; and an intake air tank forming an air intake chamber therein, which air intake chamber is provided at the downstream side of the supercharger with respect to an intake air flow direction and stores the intake air. The air intake chamber structure further includes an intake pipe formed as a separate body from the intake air tank and mounted on the intake air tank. The intake pipe serves as an inlet of the air intake chamber and projects inward of the air intake chamber. A projecting end portion of the intake pipe has a passage area that increases toward the downstream side in the intake air flow direction.