Internal Combustion Engine Control Device

An internal combustion engine control device includes a valve closing time calculation unit, a valve closing delay time difference calculation unit that normalizes a plurality of valve closing delay times with a fuel pressure and calculates a valve closing delay time difference, a content rate calculation unit that calculates the synthetic fuel content rate of a fuel stored in a fuel tank based on characteristic data indicating the relationship between the valve closing delay time difference and the synthetic fuel content rate of synthetic fuel contained in the fuel, and a combustion control unit that controls an internal combustion engine such that the exhaust temperature of an exhaust gas discharged from a combustion chamber becomes equal to or higher than a threshold temperature based on the synthetic fuel content rate.