To reduce capacity of an oil pump, and to simplify its transmission system, while simultaneously using splashing type lubrication and forced type lubrication in a vertical engine.

This vertical engine is formed by arranging a timing belt 27 in a belt passage 28 formed in a cylinder block 14 and communicating the inside of a crankcase 2 and a valve system chamber 23. A belt chamber 28 is arranged on a lower side wall of the cylinder block 14, and a bottom part in the crankcase 2 is formed in an oil reservoir 30. A transmission device 33 is connected to a crankshaft 1 adjacently to a driving timing pulley 25, and is connected with an oil slinger 31 splashing oil by soaking a part in the oil of the oil reservoir 30 and a pump driving shaft 42 of an oil pump 32 soaked in the oil of the oil reservoir 30. A delivery port 50 of this oil pump 32 is communicated with a lubricating oil passage 66 in the crankshaft 1.