PURPOSE: To obtain chromium oxide suitable to spraying and refractory materials, etc. easily at a relatively low temperature and in a short time, by adding an alkali (earth) metal salt to chromium oxide powder, calcining the resultant mixture under heating, washing the calcined material with water, and removing soluble salts.

CONSTITUTION: A metal salt selected from alkali metal salts or alkaline earth metal salts in an amount of 20wt% or less based on chromium oxide powder is added thereto, and the resultant mixture is calcined under heating. The resultant calcined material is washed with water to remove soluble salts. Carbonates, hydroxides, chromates, dichromates, chlorides, sulfates, etc. may be cited as the alkali (earth) metal salts, and particularly preferably the above-mentioned salts of Na, K, Li, and Ba may be cited. The amount of the alkali (earth) metal salt to be added depends on the desired particle diameter, but in most cases, the amount thereof to be added is preferably within 1W15wt% range.