Lead selenide thin films composed of nanoparticles and laminar structures were deposited on glass substrates by a chemical bath deposition technique, and then thermally oxidized in oxygen atmosphere at an annealing temperature of 400 °C for 20 min. The particles and laminar structures deposited were randomly dispersed and well crystalized according to the hexagonal structure with the preferential orientation (200). The energy dispersive spectrum analysis confirms that the heat treatment introduced oxygen elements into the thin film while reducing the amount of iodine and selenium. The structural, surface morphological and electrical properties of the thin film were determined using various techniques including X-ray diffraction, scanning electron microscopy, and energy dispersive and X-ray analysis. A 3×3 mm² sized photoconductive detector was patterned, and its IR response under a blackbody radiation was also discussed.