Provided are a touch sensor and a method of operating the same. The touch sensor includes: a pulse signal generator for generating a pulse signal of which pulse width is calibrated in response to a control code; a pulse signal transmitter for transmitting the pulse signal when a touch object is out of contact with a touch pad and stopping transmitting the pulse signal when the touch object is in contact with the touch pad; a pulse signal detector for detecting the pulse signal transmitted through the pulse signal transmitter; and a controller recognizing a non-contact state and adjusting the control code to calibrate the pulse width of the pulse signal when the pulse signal detector detects the pulse signal. In the above-described configuration, the contact of the touch object with the touch pad can be sensed more precisely, and the occurrence of a malfunction in the touch sensor due to changed operating conditions can be prevented. As a result, the operating reliability of the touch sensor can be enhanced.