Abstract: Crushing finely the chipped rubber such as that of waste tire is done by further small number of crushers, and the capture rate of the target size of the rubber particles is improved. With a crusher which finely crushes the chipped rubber (G) such as that of waste tire, the chipped rubber (G) is supplied to a crusher (10a) structured by a rotating roll (12) having relatively rough groove pitch and pluralities of fixed blades (14) each of which has pluralities of grooves forming crushing edges, thus conducting crushing. The rubber particles (G) discharged from the crusher (10a) are again supplied to the crusher (10a) to repeat the crushing to conduct rough-finishing operation. Then, thus roughly-finished rubber particles (G) are treated by similar crushing operation using a rotating roll (10b) having relatively small groove pitch to conduct finish treatment. The finely-crushed rubber particles are classified using a sieve (16) to specified size ranges.