Photo-cross-linkable polymers having degradable properties on heating were described. Copolymers of esters or salts of p-styrenesulfonic acid with a novel monomer having both an epoxy moiety and a tertiary ester moiety were synthesized and characterized. Polymer films containing a photoacid generator became insoluble in organic solvents on UV irradiation. The insoluble fraction of the irradiated films was increased by post-exposure-baking at relatively low temperatures (40−100 °C). When the cross-linked polymer films were baked at 120−200 °C, they became soluble in water. The effective bake temperature was dependent on the polymer structure. Thermal degradation of the cross-linked polymers was studied by TGA analysis and in situ FT-IR spectroscopy.