A thermosetting electroconductive paste composition includes an electroconductive powder (A) containing at least one of a silver-coated metal powder (A-1) and a powder of either copper or an alloy thereof (A-2), a thermosetting ingredient (B) containing at least one of an epoxy resin (B-1) and a blocked polyisocyanate compound (B-2), a hardener (C), and an alkyl- or alkenylsuccinic acid compound (D) which is a succinic acid or derivative thereof having an alkyl or alkenyl group having a carbon number of from 8 to 24 introduced into an α-position. An amount of the alkyl- or alkenylsuccinic acid compound is 0.01 to 1.8 parts by mass per 100 parts by mass of a sum of the electroconductive powder (A) and the thermosetting ingredient (B).