A touch sensor has a support layer (12) of an insulating material and a resistive layer (13) applied to the support layer. A resistive material is shaped according to an elongated pattern forming a sequence of touch positions, and has a single terminal (16) to be coupled to a sense input (17) of a detecting device (11), while an open end (15) of the sequence opposite to the terminal end remains unconnected. The detecting device detects an active resistance (Rp) between the single terminal and one of said touch positions that is touched by a user via a return capacitance constituted (Cu) by the user and a mass element (18) coupled to the detecting device. Advantageously only a single terminal is necessary, whereas a number of touch positions can be discriminated.