Stress is a major problem in modern society. Therefore, much research has focused on its reduction. Previous research has reported that people are relaxed by watching 2D video of natural environments. In recent years the virtual reality (VR) market has begun to grow, and the amount of such types of relaxation continues to increase. However, research has failed to clarify the difference of relaxation effect obtained by watching relaxing video between a 2D display and a HMD. In this research, we presented relaxing video and compared the relaxation effects of two types of displays. We used a questionnaire (POMS2), bio-signals (ECG), and salivary α-amylase tests to evaluate the relaxation effects.