Nuclear fusion reactors are among the perspective approaches in producing energy. Among the technical challenges is the selection of plasma facing materials and their lifetime characterization prior to the implementation in the fusion devices. Presently, tungsten is selected as the plasma facing material in the International Thermonuclear Experimental Reactor (ITER). For the plasma reactions, the boron introduction in the plasma is planned. There are studies on boron containing compounds, however, the information gap of thin film behaviour under thermal loads needs to be filled. The aim of the present research is to characterize the behaviour of thin tungsten-boron films under thermal loads. W-B films with a thickness of 150 nm were deposited on the Si/SiO2 substrate by the magnetron sputtering technique. The synthesized films were characterized by means of exoelectron emission and Fourier transform infrared spectrometry (FTIR). The thermal load in a way of heating was applied up to 600 °C for 6 hours. Changes in the chemical bonds were determined by means of FTIR. The obtained results of tungsten-boron films were compared with pure tungsten thin films. It was observed that thermal treatment leads to formation of W-O, W=O and oxidized boron containing compounds. Exoemission of tungsten films takes place at 410 °C, while films with boron addition give exoemission peak at around of 485 °C. The obtained results will be applied for recommendations for lifetime prediction of boron containing tungsten films in fusion devices.