Electrostatic capacitance sensor

An electrostatic capacitance sensor comprising a sensor electrode, and a detection device for detecting a contact or approach action of a detectable object with respect to a detection region based on a change in the capacitance of the sensor electrode,

• the electrostatic capacitance sensor comprising a conductor provided in the detection region,
• the conductor being disposed opposite to the sensor electrode with a gap therebetween or with a dielectric interposed therebetween,
• the area of the conductor, as viewed from a direction in which the sensor electrode and the conductor face each other, being larger than the area of the sensor electrode, and a part of the conductor facing the sensor electrode,
• the detection device comprising a detection part for detecting a change in the combined capacitance of the capacitance of the conductor and the capacitance of the sensor electrode as a change in the capacitance of the sensor electrode, and a control part, and
• the detection part comprising a CV amplifier for converting the change in capacitance into a change in voltage, and the control part being configured to detect the contact or approach action of the detectable object with respect to the detection region based on a detection signal corresponding to the change in voltage output from the detection part.