To produce a black matrix substrate for a color filter which gives high resolution and little residue after alkali development.

A coating film comprising a black resist is exposed and developed with an alkali developer to produce a black matrix substrate. In this process, a resist containing a black pigment, a copolymer having carboxyl groups, photopolymerizable monomers and a photopolymn. initiator is used, and a combination of the resist and an alkali developer is selected in such a manner that the combination shows characteristics that after development, particles present in the alkali developer has ≤1 μm max. diameter. The selected resist is applied on the substrate to form a coating film. The formed coating film is exposed and then developed with the selected developer to produce the black matrix substrate. Thus, the obtd. black matrix substrate has ≤0.3 haze of openings, and the color filter and the color display panel use the obtd. black matrix.