The aim of this work was to synthesize lanthanum manganite (LaMnO3) thin films and study their properties for application in perovskite solar cells, which are increasingly being studied as an alternative to silicon solar cells. Solar cells represent a green source of energy and have a structure of several layers, and precisely the layered structure and composition of layers based on perovskite are the main subjects of research due to their high efficiency and potential for various applications. Characteristic LaMnO3 thin films were prepared from a viscous solution of metal nitrates complexed with the addition of citric acid. The synthesis was carried out using autocombustion process, but it was interrupted at the moment of gelation. The viscous precursor solution was applied to the glass substrates by spin coating method, and the crystallization of the precursor solution into the manganite phase was carried out using the newly studied technique of intense pulsed light (IPL). IPL phototreatment has proven to be a suitable, economical and effective procedure for creating the necessary thin films. As a result of the preparation, thin films with a rough surface and with a crystallized LaMnO3 structural phase and accompanying byproducts were obtained. By measuring the optical properties of the prepared materials, it was revealed that the samples had an optical gap between 1.3 and 1.5 eV. The obtained values agreed with other studied materials that found their use in the structure of solar cells. LaMnO3 thin films obtained by exposure to intense pulsed light need to be studied in more detail and their properties need to be optimized in order to have the possibility of being used as an active layer in inorganic perovskite solar cells.