Inorganic nanofibers comprise an inorganic matrix material surface functionalized with at least one metal oxide in crystalline form. The speed of the turbine may be varied to control the output frequency of the high frequency generation unit, thus controlling the output of the compression system by controlling the speed of the turbine driving the generation unit. The cutter blade is detachably attached to the tool holding chuck so as to be replaceable and is arranged so as to cut the sheet in a state that the posture thereof is adjusted along a preset movement track.