An atomic-beam apparatus is described with which the nuclear spin and hyperfine structure separation of the ground state of the radioactive isotope 11147Ag have been found. The nuclear spin is I = 12, in agreement with the result of McGinnis and of Lemonick and Pipkin. The other experimental results are: Δν(111Ag) = 2204.54 ± 0.05 Mc/s, gJ(Ag) = 2.00235 ± 0.00012, μI(111Ag) = -0.145 ± 1% nuclear magnetons.