To provide an ignition control device of an internal combustion engine capable of reducing the number of adjustment steps required for adjustment such as matching of a MOS gate voltage or the like without being affected by device variation. A detection voltage is generated on the basis of a primary current flowing through a current detection resistor having a positive temperature dependent characteristic. A reference voltage is generated by a potential difference between a base and an emitter of a first bipolar transistor circuit and a multiple type second bipolar transistor circuit in which a plurality of bipolar transistors are connected in parallel, and a resistance value of a first resistor connected to the emitter side of the plurality of the bipolar transistor circuit, on the basis of a current having a positive temperature dependent characteristic similar to the current detection resistor.