A manufacturing method of a coordinate position detecting device includes the steps of forming the common electrode on the resistive film of tour sides of the substrate having a rectangular-shaped configuration; measuring the electric potential of the resistive film by plural probes contacting a surface of the resistive film where the electric potential is supplied from the common electrode to the resistive film; calculating a resistive film removing area, based on a value of a measured electric potential, by a calculating part so that the electric potential distribution of the resistive film is made uniform; and removing the resistive film in the resistive film removing area calculated by the calculating part, by a laser light.