Provided is a powder and granular material crushing and sizing apparatus in which stators are easy to disassemble and assemble, i.e. in which disc-like rotors and stators can be cleaned and replaced easily. A drive shaft, on which a plurality of disc-like rotors are disposed, is supported in a cantilever manner on a bearing housing. A plurality of stators are disposed on a holder to make up a stator assembly. The stator assembly is detachably disposed in the bearing housing. An opening is formed in a side wall of the casing. The disc-like rotors and the stator assembly are housed via the opening, and the casing is detachably disposed on the bearing housing. ion.