To accurately measure transparent elements with parallel surfaces, a new simple and useful method using spatial Fourier analysis technique with single three-surface interferogram is presented. It can obtain the interferometric phase from three-surface inteferogram by extracting the corresponding spectra. Therefore, the profiles of both surface and variation in thickness are calculated simultaneously. By comparing the spatial Fourier fringe analysis with phase-shifting interferometry (PSI), it can be found that the measured results are almost the same.The main errors which cause the measurement difference for the two method are given and analyzed, such as reflection from back surface, boundary problem, off-axial aberrations and homogeneity of the plate.