A copper particle mixture ensures suppression of copper oxidation and high dispersibility, and that can be sintered at a low temperature in a short period of time can suitably be used for a conductive copper ink material. The copper particle mixture contains copper fine particle A and copper nanoparticle B, the copper fine particle A having an average particle diameter of 0.1 μm to 5 μm, and being coated with at least one dicarboxylic acid selected from the group consisting of malonic acid and oxalic acid, the copper nanoparticle B comprising a central portion comprising a copper single crystal, and a protective layer surrounding the central portion, and having an average particle diameter of 1 nm to 100 nm, and the protective layer of the copper nanoparticle B containing at least one member selected from the group consisting of C3-6 primary alcohols, C3-6 secondary alcohols, and derivatives thereof.