A starting apparatus of a small-sized engine includes: a cylindrical cam; a drive gear connected to the cylindrical cam coaxially, wherein: whereas the drive gear is made to be connected to a rope reel by ratchet claws, the drive gear is made to be connected to a cell motor by at least two pieces of reduction gears; and a reduction gear in the reduction gears brought in mesh with the drive gear is divided into a small diameter gear portion and a large diameter gear portion to be arranged coaxially, side faces of the small and the large diameter gear portion opposed to each other are formed with engaging claws engaged with each other only in one direction, and the small and the large diameter gear portion are urged as the two side faces are brought into contact with each other.