Lead selenide thin films produced by hydrochemical deposition with the use of ascorbic acid as an antioxidant of selenourea have been studied by X-ray diffraction analysis, scanning electron microscopy with elemental analysis, and X-ray photoelectron spectroscopy. The effect of the annealing temperature on the elemental composition of the films, their phase composition, crystal lattice parameters, surface morphology, and photoelectric properties has been determined. It is established that, after annealing at 633–683 K, the films contain the PbSeO3, PbSeO4, and PbI2 impurity phases. The optical band gap Eg of the layers in the cases of indirect and direct transitions has been determined. It has been shown that, in terms of their threshold photoelectric characteristics, the deposited films are comparable to widely known commercial samples and can be used to produce highly sensitive infrared detectors.