In the course of the rapid progress of DUV/VUV lasers and their employment in semiconductor lithography, micro material processing, and medical surgery systems, the characterization of optical components in this spectral region gains of increasing importance. The precise determination of the optical properties, such as reflectance (R) and transmittance (T), is essential for further progresses of the components. Currently, standardized procedures for measurement of R&T are described in the international standard draft ISO/WD 15368, which is optimized for the whole wavelength range above DUV. In the DUV/VUV spectral range, scatter losses caused by the surface and bulk of the components increase with decreasing wavelengths. This effect is not considered in the standardized measurement procedures for T and R. In this study, a spectral photometer device, which has been developed at Laser Zentrum Hannover, will be presented. The set-up allows measurements of total reflectance for a defined acceptance angle range. In the current state, the DUV.VUV-photometer covers a spectral range from 115nm up to 300nm. Investigations on the scatter behavior of optics for this spectral range indicate a need for precise separation between ordinary reflected or transmitted beam and scattered radiation on the test samples. The dependence of the R and T values on the collection angles will be illustrated.