A touch sensor includes an insulative substrate; a first sensing layer, having first sensing strings arranged along a first axis, and a first interval being disposed between every two adjacent first sensing strings; and a second sensing layer, having line paths arranged along a second axis, and a second interval being disposed between every two adjacent line paths. A plurality of the line paths composes a second sensing string. Each second sensing string has an active unit and an inactive unit. The active unit is formed by one or more line paths connected by a crossing line. The line paths of the inactive units are connected to a ground line. The first sensing strings and the second sensing strings are separately orthogonally arranged on two opposite sides of the substrate. The second interval is less than the first interval in width.