Provided is an interferometer type polarized light combiner and splitter which can combine and split polarized light over a broad band. The interferometer type polarized light combiner and splitter comprises a beam splitter, an optical coupler, an optical path length difference providing unit comprised of a plurality of light guides arranged between the beam splitter and the optical coupler, one or two input/output ports connected to the beam splitter, and two input/output ports connected to the optical coupler. A standardized phase difference of the optical path length difference providing unit in two polarization states is set to be equal to one half of an integer at a wavelength lambda c. A means for differentiating a refractive index among the plurality of light guides of the optical path length difference providing unit is provided, whereby a variation of the transmittance relative to the wavelength is identical in the two polarization states.