The Sun is a star only 150 million kilometer away from the earth. The earth is full of life, not freezing cold, owing to the energy supplied from the Sun. Occasionally the Sun shows “flare explosion”, and the blast wave reaches the earth in about one day and shakes the magnetosphere and produces aurorae. In the Division of Solar and Plasma Astrophysics, we are studying the Sun from its interior to the surface and to the outer atmosphere (the corona), by using multi-wavelength data from the Hinode mission, Nobeyama Radioheliograph, and visible and infrared telescopes of Solar Observatory. Our challenge is to understand the mechanism of the Sun’s magnetic activity and its influence on the earth and human activity.