PURPOSE: To heighten the pulverizing efficiency by forming a pulverizing surface into a cone shape, to simplify the structure and to lower cost by integrally forming a conical hopper part on the upper mortar side, and to prevent an untreated material from falling from the hopper part by fitting a cover on a material feeding port of the hopper part.

CONSTITUTION: In a pulverizer consisting of a lower mortar 2 equipped with a conic pulverizing surface 2a on the inner surface side, an upper mortar 3 whose pulverizing surface 3a formed on the outer surface side coincides with the pulverizing surface 2a of the lower mortar 2 and also in which a conic hopper part is formed on the inner surface side, and a driver 8 for driving and rotating both or one of the upper and the lower mortars 3, 2, a cover 5 is freely attachably and detachably fitted on a material feeding port of the hopper part.