Touch key and induction heating cooking device employing the same

A touch key detects contact with an object. The touch key comprises an electrode section capable of touching an object, an oscillating section for applying a high frequency voltage to the electrode section, a rectifying section for rectifying and smoothing the high frequency voltage to output a DC voltage, a reference voltage generating section for generating a reference voltage, a subtracting section for subtracting the reference voltage from the DC voltage outputted from the rectifying section, and a judging section for judging contact of an object with the electrode section according to variation in output voltage from the subtracting section. The touch key can detect contact of the object with the electrode with high sensitivity and enhance reliability of the judging section.