We report on polarization sensitive imaging of two-dimensional photonic crystal microcavity modes. By using a near-field scanning optical microscope with a polarization sensitive setup, it is possible to selectively map, with a resolution beyond the diffraction limit, each electric field component in the plane of the sample. In addition, the simultaneous analysis of photoluminescence maps in different polarization channels allowed us to obtain important insight on near-field microscopy detection mechanism. Finite difference time domain simulations confirm the experimental results.