An internal combustion engine ignition device can determine ignition timing with high precision to perform ignition with high precision even where noise superimposed at the time of rise of current flowing through an ignition coil is generated. In an internal combustion engine ignition device including an output terminal for detecting an internal state such as a coil current, it is possible to prevent generation of pulse noise in the form of chattering at falling and rising edges of a voltage of the output terminal by using a hysteresis comparator, even if noise is superimposed at the time of rise of the coil current. Therefore, a voltage pulse with pulse width of high precision is transmitted to an electronic control unit without the influence of noise, and the ignition timing can be determined properly with high precision.