Theoretical and experimental demonstrations of a static spectroscopic ellipsometer are presented. It uses a linear polarizer for generating polarization states to interact with the sample, and three non-polarization beam splitters incorporating four achromatic quarter waveplate/linear analyzer pairs for analyzing the polarization states after the interaction. Compared to previous instruments, the most significant advantage of the described model is that it can obtain the spectral ellipsometric parameters with the same spectral resolution as the spectrometer in the system by a single snapshot. © 2023