PURPOSE: To obtain the subject paste composed of fine powder, such as copper- based fine powder, an electron radiation curing resin and dicarbonyl compound in a specific proportion and excellent in initial electric conductivity with maintained reliability for a long period at high temperatures and humidities without migration.

CONSTITUTION: The objective paste composed of a blend composed of (A) 60-90wt.%, preferably 70-90wt.% copper- and/or nickel-based fine powder (e.g. dendritic copper powder or nickel carbonyl powder) and (B) 40-10wt.%, preferably 30-10wt.% electron radiation curing resin (e.g. an unsaturated polyester resin) and (C) a 1,3-dicarbonyl compound [e.g. acetylacetone or (meth) acryloylacetone] in an amount of 0.05-10wt.%, preferably 0.1-5wt.% based on the total amount of the blend.