The composition for preventing development-defects containing (1) an ammonium salt, a tetraalkylammonium salt or a C1 to C4 alkanolamine salt of C4 to C15 perfluoroalkylcarboxylic acid, C4 to C10 perfluoroalkylsulfonic acid and perfluoroadipic acid, or (2) a fluorinated alkyl quaternary ammonium salt of inorganic acid, wherein said surfactant is formed at the equivalent ratio of acid to base of 1:1-1:3 is applied on a chemically amplified photoresist coating on a substrate having a diameter of 8 inches or more. The chemically amplified photoresist coating is baked before and/or after applying the composition for preventing development-defects described above. Then, the baked coating with the development-defect preventing composition coating is exposed to light, post-exposure-baked, and developed. By this process, compared with the case of not using the composition for preventing development-defects, the amount of reduction in film thickness of the photoresist subsequent to development treatment is made further bigger by 100 Å to 600 Å, and the development-defects on a substrate having a diameter of 8 inches or more is reduced as well as a resist pattern having a good cross section form can be formed without T-top form etc.