As a new power semiconductor material, gallium oxide is attracting much attention. Compared with traditional wide band-gap semiconductors such as silicon carbide and gallium nitride, it has exceeded the band gap value, and its conductivity is very high, with less lose. Among them, α-Ga₂O₃ is a new material from Japan, which is manufactured by non-vacuum process' Mist-CVD '. The current situation and practical application of this material will be introduced this time.