To provide a coordinate position detecting method for preventing increase of costs and for improving resolution without generating the increase of costs and a display device using this.

This method detects a coordinate position, at which an optical passage constituted between each of light-emitting elements 12A and light- receiving elements 12B which are arrayed with prescribed intervals in a horizontal direction and a vertical direction so as to be faced to each other is interrupted. In this case, the array intervals of either the light-emitting elements 12A or the light-receiving elements 12B are made different from the other array intervals, and the light-emitting elements 12A are allowed to emit light beams to the light-receiving elements 12B with directional angles correspond to the array intervals of the elements. Thus, it is possible to calculate a coordinate position, at which the light beams are interrupted from the coordinate positions of the light-receiving elements 12B, to which the oblique components of the light beams are scheduled to be made incident and the coordinate positions of the light-emitting elements 12A which emit the light beams to the light- receiving elements 12B.