An apparatus for controlling an inverter circuit of an induction heat cooker which generates and outputs high voltage power to cook food contained in a cooking container is disclosed. The apparatus varies a pulse width of high level interval of a driving pulse according to a level of AC power supplied thereto to vary a switch current of the inverter circuit, and sufficiently secures a turn off time of the driving pulse in proportion to a resonant time varying according to states of separation of the cooking container or the heated food. Therefore, the apparatus improves stability of the switching operation and endurance. Also the apparatus requires relatively low manufacturing costs as the trigger generation is implemented with relatively low-priced amplifiers.