Fe–Ni alloy cluster-assembled films were obtained by a plasma–gas-condensation-type cluster-deposition method. We studied the magnetic and electrical properties of these assemblies prepared on an electrically grounded substrate [bias voltage (Va) = 0 kV] and on a negatively biased substrate (Va = −20 kV). The packing density and saturation magnetization per volume, Ms, are much larger for the assemblies prepared at Va = −20 kV than those prepared at Va = 0 kV, while the magnetic coercivity, Hc, and electrical resistivity, ρ, are much lower for the assemblies prepared at Va = −20 kV than those prepared at Va = 0 kV. For Ni-rich Fe–Ni alloy cluster-assembled films obtained at Va = −20 kV, the Hc values can become smaller than 160 A/m (the precision limit of our superconducting quantum interference device magnetometer) by adjusting the initial cluster size. The magnetic and electrical properties of Fe–Ni cluster-assembled films are much improved in comparison with those of pure Fe cluster-assembled films.