To provide a color filter for a charge coupled device(CCD) which is stable at and under a high temp. and high humidity or is stable to a change in pH.

A chromatic filter element is placed on a substrate. The filter element is formed of a positive type resist compsn. contg. an alkaline soluble resin, quinonediazide compd., cross-linking agent, dyestuff and solvent. The color filter is stable at and under the high temp. and highhumidity and is adequate for applications where the filter is used in such environment, for example, the CCD of an endoscopic microscope.