Abstract: A heating apparatus for microwave ovens, electric ovens, gas ovens and ovens of the hybrid type, includes a digital control unit and a numerical display unit. The heating apparatus further includes numerical value input means (an impulse generator) including a digit change-over switch and increment/decrement switch as means for entering a numerical value such as a heating time or a heating temperature into the digital control unit. The digit change-over switch always directs one of the hours, minutes and seconds, and the increment/decrement switch is designed so that the switch which is usually held off is closed only when the knob is moved or when the knob is depressed, for example, and the switch is returned to the original off position upon releasing the hand, thus reducing the number of setting keys, lessening the possibility of erroneous setting and simplifying the setting of heating time and heating temperature.