Tungsten thin films were deposited in the metastable beta phase, and their stress response to thermal cycling was evaluated in a high-vacuum environment. The stress behavior is analyzed at different stages, and the change from the beta phase to the stable alpha phase is marked by a noticeable rise in tensile stress. Different amounts of nitrogen were added to the films. A thin film with a higher nitrogen content exhibits a greater stress change throughout the thermal cycling process, demonstrating the critical role of nitrogen in influencing phase stability, which is important for building magnetic random-access memories.