The present invention relates to a highly conductive electrolyte comprising an ionic liquid and to a polymer electrolyte membrane using same, and more particularly, to a highly conductive polymer electrolyte membrane impregnated with a heterocyclic diazole-based ionic liquid and to a method for manufacturing same. The present invention relates to a polymer electrolyte thin film comprising an ionic liquid based on an imidazole compound represented by chemical formula (1), wherein R1 is an alkyl having a carbon number of 1 to 8 and R2 is hydrogen or an alkyl having a carbon number of 1 to 8: