To control a heat generating rate in a combustion chamber to a wide extent and appropriately, by repeatedly performing plural times in each injection cycle, complete interruption of fuel injection and restarting of fuel injection executed after the interruption.

An internal combustion type reciprocating piston diesel engine is so arranged that first and second injection nozzles 1a, 1b eject liquid fuel to the inside of a combustion chamber 43, and an exhaust valve is arranged in the center of a cylinder head 46. The injection nozzles 1a, 1b have jet needles 7, and the jet needles 7 are energized to seat surfaces 1' by closing springs 8, lifted by being separated from the seat surfaces 1' by fuel pressure supplied to pressure chambers 10 so that fuel is ejected from injection holes 2. When fuel injection is controlled, complete interruption of fuel injection and restarting of fuel injection executed after the interruption are repeated plural times in each injection cycle, hereby, a heat generating rate in the combustion chamber 43 is suppressed so that high efficiency and low fuel consumption corresponding to the high efficiency can be realized.