PURPOSE: To provide a knocking control device for properly controlling knocking by retarding an amount of knocking signal in proportion to the total pulse width of the number of knocking pulses.

CONSTITUTION: A knocking control device consists of a knocking sensor 100 to detect a knocking signal, a knocking control unit 101 generating control signal output for controlling ignition timing of a ignition coil 135 according to knocking signal output from the knocking sensor, a pick-up coil 105 for detecting spark timing of the ignition coil 135 and a contactless igniter 103. The contactless igniter 103 ignites the ignition coil with the outputs of the pick-up coil 105 and knocking control unit 101 while sending feedback signal to the knocking control unit 101 which takes the detecting signal of the knocking sensor 100 and the output signal of the contactless igniter 103 to control the unit 103 and carry out contrably angle advancing or retarding in response to knocking.