The present invention relates to a gel electrolyte comprising a cyclic sulfonic acid ester represented by formula (1). According to the present invention, it is possible to provide a gel electrolyte capable of suppressing the self-discharge of a polymer secondary battery, and a polymer secondary battery using the gel electrolyte. wherein R1 and R2 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen group or an amino group with the proviso that R1 and R2 are not hydrogen atoms at the same time; R3 represents a linkage group selected from the group consisting of an alkylene group having 1 to 5 carbon atoms, a carbonyl group, a sulfonyl group, a fluoroalkylene group having 1 to 6 carbon atoms, and a divalent group having 2 to 6 carbon atoms in which alkylene units or fluoroalkylene units are bonded through an ether group.