The Glasgow Climate Pact signed on the 26th Conference of the Parties of United Nations Framework Convention on Climate Change in 2021, saws representatives' determination for carbon neutrality by 2050. Meanwhile, "Net Zero by 2050: a Roadmap for the Global Energy Sector" proposed by International Energy Agency has suggested hydrogen as a decarbonization technology in various fields. As a clean, stable power with diverse sources, hydrogen provides a promising solution for energy, industry, and transportation, making hydrogen economy a prominent international topic, prompted developed countries actively investing in hydrogen technologies, setting out development pathways, offering policies and subsidies for short, mid and long-term goals. With net-zero by 2050 commitment, Taiwan introduced its goals in 2021, followed by "Taiwan's Pathway to Net-Zero Emissions in 2050" proposed by the National Development Council in 2022, unveiling a cross-ministerial aggregate strategy. Among its twelve key strategies leads to net zero, hydrogen plays a vital role in the field of energy, industry and transportation. In 2024, hydrogen has again been listed as a key policy for "Green growth and Net-Zero Transition by 2050", one of the eight major guidelines of "National Project of Hope". Over the past 20 years, hydrogen and fuel cell industry in Taiwan has developed a well-established value chain and abundant experience from small-scale demonstration fuel cells projects. At this focal point, it's important for Taiwan to align with the global trend towards net-zero carbon emissions and initiate research and analysis on energy. This will accelerate the implementation of large-scale hydrogen projects, allowing technological development, validation, and regulatory adaptation, further enhancing Taiwan's hydrogen industry. The purpose of this book is to provide Taiwan community a literature with comprehensive hydrogen knowledge. This publication by Taiwan Institute of Economic Research and Taiwan Hydrogen and Fuel Cell Partnership helps readers to understand hydrogen and fuel cell technologies, its applications, international and domestic hydrogen industries, policy development and trends, as well as potential development directions and application scenarios within present energy and hydrogen industry context. We hope this book can be a thrust for Taiwan to align with international trends, seize opportunities, and create a mutually beneficial, sustainable hydrogen development vision.