Ultra Fast Outflow (UFO) is a very fast (10-30% of the light speed) wind launched from
the accretion disc around a supermassive black hole in an Active Galactic Nucleus
(AGN). It is observed as an X-ray blueshifted H-like or He-like iron absorption lines in
the 7-10 keV band. Its large kinetic power may contribute to the AGN feedback, that is,
UFO may control host galaxy evolution. In the first half of this seminar, I will talk
about the launching mechanism of UFO and simulation for the XRISM observation. Very good
energy resolution of XRISM will enable us to constrain the physical condition of the UFO
gas and measure the line shift more accurately. In the latter half, I will propose the
future strategy for monitoring UFO lines. It is essential for quantitatively studying
UFO contribution to the AGN feedback.