PURPOSE: To produce silicon nitride powder having a low oxygen content and a large specific surface area at a low cost without requiring long-time or special crushing-pulverization or such purification treatment as that in wet pulverization.

CONSTITUTION: The objective pulverizing aid for silicon nitride is an org. compd. having one or more kinds of groups selected from among amine, ketone, nitrile, ether and aldehyde in each molecule but not having hydroxyl, carboxyl and/or sulfone, the b.p. of the org. compd. is <100°C and the solubility at 20°C is ≥2g/100g water. A silicon nitride ingot obtd. by direct nitriding of metallic silicon is pulverized with the pulverizing aid to produce the objective silicon nitride powder.