The present invention provides a positive photosensitive resin composition which can form a cured film excellent in process resistance such as heat resistance, solvent resistance or long-time baking resistance and transparency, and which is excellent in photosensitive properties such as resolution and sensitivity, and which has high storage stability and a wide process margin. Further, the present invention provides a positive photosensitive resin composition having such high reliability that no deterioration of electrical characteristics will be led in its application for liquid crystal display devices.A positive photosensitive resin composition characterized by comprising an alkali-soluble resin which is a copolymer essentially comprising an unsaturated carboxylic acid derivative and an N-substituted maleimide and which has a number average molecular weight of from 2,000 to 20,000, a 1,2-quinone diazide compound represented by the formula (1): (wherein each of D independently is a hydrogen atom or an organic group having a 1,2-quinone diazide group, R1 is a tetravalent organic group, provided that at least one of D is an organic group having a 1,2-quinone diazide group), and from 5 to 50 parts by weight, per the alkali-soluble resin, of a crosslinking compound represented by the formula (2): (wherein n is an integer of from 2 to 10, m is an integer of from 0 to 4, and R2 is a n-valent organic group).