Disclosed is a TiO2 nano particle exhibiting a strongly activated catalyst function. The TiO2 nano particle is created by a step of mixing Ti powder and metal powder M (M is Ni, Cr, Pt, Rh, Ru or Cu), a step of generating heat plasma, and a step of supplying a mixture of the titanium powder and the metal powder to the heat plasma using an inert gas as a carrier gas and supplying oxygen gas to the heat plasma. The created TiO2 nano particle is injected with a metal and/or a metal oxide MxOy (M is Ni, Cr, Pt, Rh, Ru or Cu, x=1, 2, 3 . . . and y=0, 1, 2 . . . ), thereby exhibiting high photocatalytic activity.