Abstract: A breather apparatus is provided in a cylinder head having an intake camshaft and an exhaust camshaft that drive an intake valve and an exhaust valve, respectively. The breather apparatus includes, spaces separated from each other by partition walls and in communication with each other through an opening formed in the partition walls, the spaces having a blow-by gas flowing from a crankcase side passing sequentially therethrough. The spaces include a first space and a second space. The first space is formed in a region between the intake valve and the exhaust valve in the cylinder head. The second space is provided across the first space from a crankcase side, separated from the first space by a partition wall disposed substantially along a plane including shaft centers of the intake camshaft and the exhaust camshaft, and receives the blow-by gas flowing from the first space.