抄録
Small unmanned aircraft called drone are rapidly utilized since 2000's. This paper will review the history of UAV (Unmanned Aerial Vehicle), firstly. Secondly, application fields will be summarized based on the type of UAVs, such as a multicopter, a helicopter and a fixed wing aircraft. Thirdly, not only technical but also non-technical problems will be considered for achieving safety operations of UAVs. Regulations to be established by ICAO and each country's authority will be examined.