A polycrystalline 57Fe-isotope-enriched sample of UFe0.40Ge2 was investigated by X-ray powder diffraction, magnetization and Mössbauer spectra measurements. The compound was confirmed to crystallize with the orthorhombic CeNiSi2-type structure (space group Cmcm) and with the lattice parameters a = 4.0759(2) Å, b = 15.8107(7) Å, and c = 4.0379(2) Å, being close to those reported previously for a very similar composition. Magnetic properties measurements showed that UFe0.40Ge2 orders ferromagnetically at TC = 37 K with the effective magnetic moment of 2.57(3) μB and the ordered magnetic moment at 70 kOe of about 0.64(1) μB, being fully consistent with the earlier report on physical properties of UFe0.39Ge2. 57Fe Mössbauer spectra measurements performed both in the field-cooled and zero-field-cooled regimes ruled out the formation of ferromagnetic cluster-glass or spin-glass state, and confirmed that the ferromagnetism in the studied system is purely long-range in nature. A small contribution of about 0.24–0.36 μB to the total magnetic moment from the iron atoms was observed.