PURPOSE: To make it possible to dissolve an electroconductive polymer by a simple process, by combining a polymer having a skeleton consisting of aryl groups and chalcogen atoms adjacent thereto with a metal halide and a specific solvent.
CONSTITUTION: This electroconductive polymer solution is formed from the following three components: a polymer (A) having a skeleton consisting of aryl groups and chalcogen atoms adjacent thereto a metal halide (B) and at least one solvent (C) selected from among an organic nitro compound, a thionyl halide and an organic halide. As component (A), a polyphenylene chalcogenide is desirable. As component (B), a Group III metal halide, a Group V metal halide or a Group V metal fluoride is desirable. As component (C), nitromethane or thionyl chloride is particularly desirable.