An object of the invention is to accurately detect a state of an object to be heated in a cooking vessel and effectively avoid cooking failure. An induction heating section (13) inductively heats a cooking vessel (11). A vibration detecting section (14) detects a vibration of the cooking vessel (11) via a top plate (12). A vibration waveform extracting section (15) extracts a vibration waveform of a frequency component having a frequency equal to a predetermined multiplication product of an induction heating frequency, from a waveform of the vibration detected by the vibration detecting section (14). A determining section (16) determines a state of an object to be heated, based on the vibration waveform extracted by the vibration waveform extracting section (15).