We have developed a spectroscopic transmission-type four detector polarimeter (T-FDP). It consists of a detector head and a multichannel spectrometer equipped with a two-dimensional CCD detector. Inside the T-FDP, three cubic beam splitters are aligned in a straight line and they are rotated relative to each other. From the responses of the spectroscopic T-FDP to five inputs with known polarization states it is possible to determine the characteristic matrices of the T-FDP at various wavelengths. The trajectories of the experimentally measured polarization states on the Poincare sphere agree well with theoretical predictions. These results demonstrate the feasibility of using the T-FDP for spectroscopic ellipsometry. (C) 2010 Elsevier B.V. All rights reserved.