A positive photoresist composition comprising a polymer, a photoactived agent and a dissolution inhibitor represented by the following formula (1): wherein R1 and R2 each independently is a hydroxyl group, a C1-8 hydroxyalkyl group, or a C3-8 hydroxycycloalkyl group; R3, R4 and R5 each independently is a hydrogen, a C1-8 hydroxyalkyl group, a C1-6 carboxylic acid or a C3-8 carboxylic acid ester; a