An apparatus and method for reading symbol information enabling improvement of decoding accuracy, not being affected by the condition of a reflection coefficient waveform of a reflected light beam and the kind of symbol information to be read. The polycrystalline silicon film has a P-type part located on the first region and an N-type part coming into contact with the P-type part and located on the second region, and the P-type part is further doped with a heavier element than a P-type impurity that determines a conductivity type of the P-type part. The equity protection product may be used to safeguard a borrower’s investment in the event of a housing market downturn.