The present invention relates to touch detection technology and provides a capacitive touch sensor which comprises a driving electrode layer and a sensing electrode layer. An insulating isolation layer is disposed between the sensing electrode layer and the driving electrode layer. A touch panel is disposed over the sensing electrode layer, and the sensing electrode layer has hollowed-out sensing electrodes. The present invention provides a new sensor structure in which the sensing electrode layer (such diamond, rectangular, round etc.) is hollowed-out to improve sensitivity of touch detection and the signal to noise ratio (SNR).