The present invention shortens an intake duct while enabling an intake of cleaner air into the inside of an air cleaner. In a vehicle in which vehicle body mounting parts such as an engine, an air cleaner and the like are supported on a vehicle body frame, a cabin is formed by mounting a pair of left and right seats on the vehicle body frame with the engine being arranged below the seats. An air cleaner is arranged behind the engine with an intake duct for sucking outside air being connected to the air cleaner. The intake duct extends frontwardly from the air cleaner while avoiding a cylinder portion of the engine with a distal end portion thereof being opened in a cabin side adjacent to the at least one seat.