To provide a motorcycle capable of improving the assemblability by reducing the number of components, stably supplying the secondary air, reducing the transmission noise such as mechanical noise, and effectively utilizing a space formed on an upper part of a cylinder head.

In this motorcycle having a car body frame 2 composed of a main frame 4 extended obliquely rear lower part and equipped with an engine 1, and a seat frame 6 equipped with a seat 20, and provided with a secondary air control mechanism part C for supplying the secondary air from an air cleaner box 19 at a rear side of the engine 1 and at a lower part of the seat 20 to an exhaust system b, and a secondary air supply device B composed of a check valve 33, the secondary air control mechanism part C and the check valve 33 are directly mounted on an upper part of a head cover 1d of a cylinder 1a formed by forwardly inclining a cylinder head 1c of the engine 1, and a secondary air passage 23 is provided along the car body frame 2 for supplying the secondary air from the air cleaner box 19 to the secondary air supply device B.