Provided are copper microparticles which have exceptional oxidation resistance, in which oxidation is reduced even when the copper microparticles are held at a firing temperature in an oxygen-containing atmosphere, and in which sintering also occurs. The copper microparticles have a particle diameter of 10-100 nm, have a surface coating material, and are such that, after the copper microparticles are held for one hour at a temperature of 400° C. in an oxygen-containing atmosphere, the particle diameter exceeds 100 nm while a copper state is retained.