Copper-diamond composite, heat dissipation member, and electronic device

A copper-diamond composite comprising:

• a plurality of diamond particles that are dispersed in a copper-based metal matrix, wherein
• the metal matrix is a sintered compact of metal powder, and
• when a particle size distribution, including shape distribution and particle diameter distribution, of the diamond particles is measured using an image particle size distribution analyzer, the particle size distribution includes information of a projected object of the plurality of diamond particles obtained by the image particle size distribution analyzer, a number average of a sphericity distribution of the diamond particles is 0.90 or more, and sphericity is calculated as X/Y, wherein X denotes the circumferential length of a circle having the same area as the projected object and Y denotes the circumferential length of the projected object.