The superprism effect was demonstrated experimentally in a thin film Fabry-Pérot filter based on its large group delay at the wavelength of peak transmittance. The group velocilty delay and the shift caused by the spatial dispersion were numerically simulated by characteristic matrix method used widely in optical thin film theory. The device was fabricated and tested and the results showed that the maximum shift of spatial dispersion due to the superprism effect reached 65 μm at the wavelength of peak transmittance, which consisted well with the design. Compared with the conventional grating element and prism, the device had smaller size and higher spatial angular dispersion, nearly 30°/nm in the range from 784.5 nm to 786.5 nm according to the measurement.