The present invention relates to a copper fine particle dispersion that contains copper nanoparticles A dispersed in the dispersion with a polymer B, and a dispersion medium C, in which the polymer B contains a constitutional unit derived from a carboxy group-containing monomer (b-1) and a constitutional unit derived from a polyalkylene glycol segment-containing monomer (b-2), a content of the polyalkylene glycol segment in the polymer B is not less than 55% by mass and not more than 97% by mass, an acid value of the polymer B is not less than 20 mgKOH/g and not more than 250 mgKOH/g, and the dispersion medium C contains at least one compound selected from the group consisting of a (poly)alkylene glycol, a (poly)alkylene glycol derivative, a terpene alcohol, glycerin and a glycerin derivative; and a method for producing a bonded body, which includes the steps of allowing the aforementioned copper fine particle dispersion to intervene between a plurality of metal members; and heating the dispersion.