In response to the "Paris Agreement" which was adopted at COP21 in December 2015, Japan has also aimed for "2050 carbon neutrality" in October 2020. Torrefaction is known as a method for maximizing the use of solid biofuels. Torrefaction treatment is attracting attention as a method for reforming solid biofuels, in addition to hydrophobically modify biomass for material use. Biomass subjected to torrefaction treatment has significantly improved its properties such as lower moisture content, higher energy density, higher crushability, and hydrophobicity when compared to that of raw material biomass, so it has the potential for industrial use. In this article, we explained the dry torrefaction (DT) and wet torrefaction (WT) methods. Finally, we also discussed the prospects of torrefaction solid biofuels in Japan. In any case, the transition to green energy and renewable energy through solid bioenergy is inevitable.