The soft magnetic properties of electrodeposited CoNiFe films were studied. Films composed of 30∼50 wt%Co-23∼35 wt%Ni-25∼35 wt%Fe alloy with a high saturation magnetization of more than 1.5 T show a low coercivity of less than 0.2 Oe. A film composed of 40Co-30Ni-30Fe alloy and having an fcc phase structure with small bcc phase, which was created by annealing at 300°C, has excellent soft-magnetic properties (H_c=0.06 Oe, μ=3200, B_s= 1.8 T). This bcc phase makes an appearance during the first stage of crystallization at 287°C. The structure is thermally unstable, and is due to a special feature of electrodeposition. During the annealing, H₂O, H₂, and CO₂ were released from the film, but the patterns of generation of these gases bear little relationship to the DSC pattern.