The present invention relates to a photosensitive resin composition for use as a photoresist, and more particularly, to a photosensitive resin composition for a photoresist comprising an acrylate copolymer obtained by selectively using specific compounds or controlling the ratio of unreacted monomers, and a 1,2-quinonediazide compound, which is excellent in several performance factors such as dielectric characteristics, flatness, transparency, developing performance, residual film rate, chemical resistance, and heat resistance, as well as sensitivity and resolution, and in particular it facilitates easy pattern formation into interlayer dielectrics, and it can be used as a photoresist in an LCD manufacturing process due to its excellent transmissivity even when prepared as a thick film.