A capacitive touch sensor includes two sensing layers. Each sensing layer has sensing strings, each of which is composed of sensing units connected in series. An end of each sensing string is provided with a contact. Each sensing string has a wire. Each wire electrically connects to one of the contacts and a string of the sensing units. A transparent insulative layer is arranged between the two sensing layers. The two groups of sensing strings on two the sensing layers interlace with each other to form a sensing matrix.