In order to reduce the micro-particles emitted from automobiles and to prevent global warming phenomena due to the CO2 gas emission, the commercialization and the distribution of fuel cell vehicles (FCVs) are underway. Therefore, the development of FCVs and the spread of hydrogen stations are carried out around the world. Recently, with the expansion of the hydrogen energy use, it is very important to ensure the safety and reliability of tanks and containers for highly pressurized H2 gas. To so do, the establishment of a simple test method for securing various materials used to hydrogen energy facility and for confirming the reliability with long-time use is needed. In this study, the hydrogen embrittlement behaviors for various metallic materials for hydrogen energy under pressurized H2 gas environment were investigated.