After an alloy powder including W, Cr, at least one of Ti, Zr, and Hf, and at least one of V, Nb, and Ta is produced, the alloy powder, a powdery carbon material, and a catalyst are heat-treated in the presence of a nitrogen gas. The alloy powder is carbonitrided into a multicomponent ceramics powder, and sintered into a sintered body. Alternatively, a powder of a first substance including at least two of Ti, Al, V, Nb, Zr, Hf, Mo, Ta, Cr, and W is molded into a molded body. Then, the surface of the molded body is surrounded by a second substance including a metal element which is not contained in the powder of the first substance, and the molded body is heat-treated in an atmosphere in which N is present. A porous sintered body thus produced is crushed into a multicomponent ceramics powder.