Ignition device for an internal combustion engine

A one-chip integration circuit including a power part and a control part integrated within an IGBT monolithic silicon substrate (36) is disclosed. The control circuit part comprises a current limiting circuit (18) for limiting a current so that it does not flow over a set-up value, a reference pulse generating circuit (30) for detecting that an ignition control signal is inputted over a predetermined period of time, a digital timer made up by a digital counter (31), a latch circuit (32) for dropping the gate voltage of the IGBT by latching due to the digital timer output signal and carrying out resetting when the ignition control signal is off, an input circuit (24) having a potential comparison circuit in its input stage, in which the operation voltage for ignition control signal has a threshold value and a hysterisis, and an input protection circuit (27) having a Zener diode (78) and a resistor (76) connected in parallel therewith for protecting the element from disturbance surges. A one-chip igniter with high operative stability and high reliability can be provided.