[en] Strong violet-blue photoluminescence (PL) band peaked at around 410 nm was obtained in Ge oxide films fabricated using magnetron sputtering of single crystal Ge target in diluted O₂. The peak position of this band remains unchanged with annealing temperature, but its intensity has a maximum in the sample annealed at 600 deg. C and almost vanishes in the samples annealed over 700 deg. C. PL excitation spectral examinations reveal that the origin of this band is different from that of the violet 395 nm PL band, which was frequently observed in Ge oxide and attributed to GeO color centers. The experimental results from Raman scattering and X-ray diffraction spectroscopy suggest that the 410 nm PL band arises from optical transition in the Ge neutral oxygen vacancy centers. Our experiments provide effective arguments for judging the existence of the neutral oxygen vacancy centers