An amorphous equiatomic FeCrMnNiC alloy thin film was synthesised on silica and silicon substrates by ion beam sputter deposition. Scanning electron microscopy energy-dispersive X-ray spectroscopy, X-ray diffraction, selected area electron diffraction and nano indentation were used to investigate the material. The produced film is amorphous and uniform on the atomic level without any detectable element segregation. The corrosion properties were assessed in 3.5% NaCl solution. The FeCrMnNiC alloy has corrosion resistance better than corrosion resistance of 304 SS. The thin film has hardness at around 12.3 ± 0.5 GPa and reduced Young’s modulus at around 222 ± 12 GPa.