Metastable Co&sngbnd;Cu solid solutions in the concentration range between 12% and 95% Cu were obtained by simultaneous evaporation of Co and Cu on a cold substrate. The spin moment of the as‐deposited alloys is equal to that of Fe&sngbnd;Ni, Co&sngbnd;Ni, Ni&sngbnd;Cu solid solutions with the same average number of electrons per atom. During annealing at 700°C for a suitable time the spin moment increases to the value calculated for the two‐phase equilibrium state of the alloys. For an alloy with 65% Cu the Curie temperature is 580°K. All alloys have fcc structure before and after annealing.