Ignition timing control device for an internal combustion engine

Ignition timing control device for an internal combustion engine, having a first detector (200) for detecting intensity values ​​relating to an intensity of vibration caused in an internal combustion engine (100) in a first interval of crank angle in a plurality of ignition cycles, Vibration generated a second detector (200) for detecting the waveforms in the internal combustion engine (100) in a predetermined second interval of crank angle in the plurality of ignition cycles, a memory means (202) for previously storing a waveform of vibration of the internal combustion engine (100) a calculation means (200) for calculating a value relating to a deviation between the detected waveform and the stored waveform based on a result of comparison between the detected waveform and the stored waveform, and is a control means (200) for controlling the ignition timing of the internal combustion engine (100) based on an intensity value of the plurality of intensity values ​​which is smaller than a predetermined first value (V (1)), and an intensity value in an ignition cycle in which a value relating to a deviation larger than a predetermined second value (K (1)) is calculated, wherein said calculating means (200) contains a value relating to a deviation between a detected waveform due to operation of a predetermined component, a vibration waveform (104, 108, 166, 118) of the internal combustion engine (100), and the stored waveform is determined such that it is less is defined as a value relating to a deviation between a detected waveform that does not include the vibration waveform due to the operation of the predetermined component, and the stored waveform.