Abstract: A two-cycle engine includes a starting fuel supply passage for supplying a starting fuel to a crankcase from a starting fuel reservoir, and a flow passage opening and closing unit provided in a midway portion of the starting fuel supply passage. The starting fuel supply passage is opened to be constantly in communication with the crankcase. Accordingly, simultaneously with the generation of a negative pressure within the crankcase when a piston starts to ascend from a bottom dead center, the starting fuel starts to be supplied to the crankcase. Since the starting fuel is supplied to the crankcase for a relatively long time as compared to a conventional engine, a sufficient amount of the fuel is supplied for starting and startability of the two-cycle engine is improved.