A straddled vehicle comprising: an engine including a plurality of combustion chambers; a supercharger; an intake passageway that defines an intake passage in which intake air sucked in from atmosphere may flow to each of the plurality of combustion chambers; and a throttle valve positioned in the intake passageway, wherein: the supercharger is positioned upstream from the throttle valve with respect to a direction of flow of intake air in the intake passageway; the intake passageway includes a downstream-side intake passageway that is positioned downstream from the throttle valve with respect to the direction of flow of intake air in the intake passageway; the downstream-side intake passageway includes: a plurality of branch intake passageways that are provided for the plurality of combustion chambers on a one-to-one basis in such a manner that branch intake passages defined by the respective branch intake passageways lead to the corresponding combustion chambers; characterized in that, the downstream side intake passageway further includes: a single common intake passageway that is connected to the respective upstream ends of the plurality of branch intake passageways with respect to the direction of flow of intake air in the intake passageway in such a manner that a single common intake passage defined by the common intake passageway leads to each of the branch intake passages defined by the respective branch intake passageways; the upstream end of the common intake passageway is at a place where the throttle valve is positioned; and the inner volume of the common intake passageway is smaller than the total inner volume of the plurality of branch intake passageways. an engine including a plurality of combustion chambers; a supercharger; an intake passageway that defines an intake passage in which intake air sucked in from atmosphere may flow to each of the plurality of combustion chambers; and a throttle valve positioned in the intake passageway, wherein: the supercharger is positioned upstream from the throttle valve with respect to a direction of flow of intake air in the intake passageway; the intake passageway includes a downstream-side intake passageway that is positioned downstream from the throttle valve with respect to the direction of flow of intake air in the intake passageway; the downstream-side intake passageway includes: a plurality of branch intake passageways that are provided for the plurality of combustion chambers on a one-to-one basis in such a manner that branch intake passages defined by the respective branch intake passageways lead to the corresponding combustion chambers; characterized in that, the downstream side intake passageway further includes: a single common intake passageway that is connected to the respective upstream ends of the plurality of branch intake passageways with respect to the direction of flow of intake air in the intake passageway in such a manner that a single common intake passage defined by the common intake passageway leads to each of the branch intake passages defined by the respective branch intake passageways; the upstream end of the common intake passageway is at a place where the throttle valve is positioned; and the inner volume of the common intake passageway is smaller than the total inner volume of the plurality of branch intake passageways. the supercharger is positioned upstream from the throttle valve with respect to a direction of flow of intake air in the intake passageway; the intake passageway includes a downstream-side intake passageway that is positioned downstream from the throttle valve with respect to the direction of flow of intake air in the intake passageway; the downstream-side intake passageway includes: a plurality of branch intake passageways that are provided for the plurality of combustion chambers on a one-to-one basis in such a manner that branch intake passages defined by the respective branch intake passageways lead to the corresponding combustion chambers; characterized in that, the downstream side intake passageway further includes: a single common intake passageway that is connected to the respective upstream ends of the plurality of branch intake passageways with respect to the direction of flow of intake air in the intake passageway in such a manner that a single common intake passage defined by the common intake passageway leads to each of the branch intake passages defined by the respective branch intake passageways; a plurality of branch intake passageways that are provided for the plurality of combustion chambers on a one-to-one basis in such a manner that branch intake passages defined by the respective branch intake passageways lead to the corresponding combustion chambers; characterized in that, the downstream side intake passageway further includes: a single common intake passageway that is connected to the respective upstream ends of the plurality of branch intake passageways with respect to the direction of flow of intake air in the intake passageway in such a manner that a single common intake passage defined by the common intake passageway leads to each of the branch intake passages defined by the respective branch intake passageways; the upstream end of the common intake passageway is at a place where the throttle valve is positioned; and the inner volume of the common intake passageway is smaller than the total inner volume of the plurality of branch intake passageways.