A method of optimizing a layout of selected parts to be cut from a piece of raw material such as wood, uses data representing geometric and defect-related characteristics of the each piece and data representing geometric and grade characteristics of a set of parts to be cut. The fibrous particle generating apparatus includes a base material containing a fibrous material; a holding unit holding the base material; a fibrous particle generator generating fibrous particles by chafing the base material; and a movement unit moving the holding unit such that the base material held by holding unit is chafed against the fibrous particle generator. The active material layer constituted by at least two elements is readily formed with excellent reproducibility, and its composition can be readily controlled by independently controlling power applied to the first sputtering source and the second sputtering source.