A mobile phone 100 having a capacitive touchpad unit 102 includes a touch sensor circuit 121 that outputs measurement values each indicating a capacitance of the touchpad unit 102, a computing unit 111a that computes a sensor output value based on each measurement output from the touch sensor circuit 121, a calibration coefficient updating unit 111a3 that updates the sensor output value by updating a calibration coefficient so as to be equal to a predetermined reference value, a judging unit 118 that detects a contact based on the sensor output values, and a judgment threshold switching unit 133 that causes the judging unit 118 to use a provisional contact-judging unit for a time period starting when the update occurs during the time that the user's face is in contact with the touchpad unit 102 and ending when it is judged that the touch to the touchpad unit 102 is released.