A control apparatus of a compression self-igniting internal combustion engine that is configured to carry out combustion by self-ignition of fuel injected from a fuel injection valve into a combustion chamber in accordance with a fuel injection amount instruction value, wherein the control apparatus comprises a combustion deterioration determining means configured to compare a reference heat production efficiency that is a constant value and a maximum value of an amount of heat generated per volume unit of fuel in a predetermined inspection target period including at least part of combustion period of the fuel injected with an actual heat production efficiency that is a value obtained by dividing an amount of heat actually generated in the inspection target period by a fuel injection amount instructed by the fuel injection amount instruction value, and configured to determine whether there is an occurrence of combustion deterioration in the combustion chamber based on a deviation amount of the actual heat production efficiency with respect to the reference heat production efficiency, characterized in that the control apparatus further comprising a correction means configured to carry out correction for a fuel injection mode, when the deviation amount of the actual heat production efficiency with respect to the reference heat production efficiency exceeds a predetermined threshold value, and the combustion deterioration determining means determines that the combustion state in the combustion chamber is deteriorated, wherein the correction means is configured to carry out increase correction for the fuel injection amount when the actual heat production efficiency is lower than the reference heat production efficiency, the deviation amount exceeds a predetermined threshold value, and the combustion deterioration determining means determines that the combustion state in the combustion chamber is deteriorated, wherein the correction means is configured to carry out decrease correction for the fuel injection amount and carry out increase correction for an amount of oxygen introduced to the combustion chamber when the deterioration of the combustion state is not improved by the increase correction for the fuel injection amount. wherein the control apparatus comprises a combustion deterioration determining means configured to compare a reference heat production efficiency that is a constant value and a maximum value of an amount of heat generated per volume unit of fuel in a predetermined inspection target period including at least part of combustion period of the fuel injected with an actual heat production efficiency that is a value obtained by dividing an amount of heat actually generated in the inspection target period by a fuel injection amount instructed by the fuel injection amount instruction value, and configured to determine whether there is an occurrence of combustion deterioration in the combustion chamber based on a deviation amount of the actual heat production efficiency with respect to the reference heat production efficiency, characterized in that the control apparatus further comprising a correction means configured to carry out correction for a fuel injection mode, when the deviation amount of the actual heat production efficiency with respect to the reference heat production efficiency exceeds a predetermined threshold value, and the combustion deterioration determining means determines that the combustion state in the combustion chamber is deteriorated, wherein the correction means is configured to carry out increase correction for the fuel injection amount when the actual heat production efficiency is lower than the reference heat production efficiency, the deviation amount exceeds a predetermined threshold value, and the combustion deterioration determining means determines that the combustion state in the combustion chamber is deteriorated, wherein the correction means is configured to carry out decrease correction for the fuel injection amount and carry out increase correction for an amount of oxygen introduced to the combustion chamber when the deterioration of the combustion state is not improved by the increase correction for the fuel injection amount.