To provide a pulverizing apparatus for waste gypsum board which is capable of finely pulverizing waste gypsum boards and separating them into gypsum debris and pasteboard pieces.

A pair of pulverizing wheels 7, 8 having claw blades (a) are installed in a casing 15. A throwing inlet 18 for wastes W and a discharge outlet 19 for crushed matter are formed in the upper end and the lower end, respectively, of the casing 15. A crushing means B for crushing pulverized matter dropped out of the discharge outlet 19 and further finely pulverizing the matter is installed and a sorting member C having a fluidized face (c) of the resultant pulverized matter and a large number of small holes (d) are correspondingly installed under the crushing means B. A storage bag 30 for gypsum debris is set in the lower part of the small holes d and a storage box 31 for pasteboard pieces is installed in the downstream end part of the fluidized face c.