Engine knock detection device

An engine ECU executes a program including a step (S108) includes at which the knock intensity N based on the comparison of a waveform that is detected as a waveform of a vibration, which goes back to a tapping, with a knock waveform model, which as waveform of a vibration that is due to knocking is stored in the memory, for the crank angle, apart from the crank angles where the magnitude of a vibration not attributed to knocking is larger than a predetermined magnitude, is calculated (a step S112 wherein it is determined that the engine knocks when the knock intensity N is larger than a predetermined reference value (YES at step S110), and (a step S116), where it is determined that the engine does not knock when the knock intensity) N is not greater than a predetermined reference value (nO at S110).