On 27th, May 2022, Imamura was invited by the Nagano Industrial and Commercial Encouragement Organization (NICE) as a speaker on the annual meeting. Imamura talked a keynote speach entitled "Potentials and Technologies of Hydrogen - For the Alternative Energy-". Imamura introduced the recent circumstances of developing to utilize hydrogen in worldwide and some exapmles of physical risk evaluation of hydrogen focusing to its strong flammability. I hope that to excite wider activities to develop state-of-the-art susitanable society based on innovative technologies which used hydrogen with safety and effective.