To obtain a binder for granulation capable of sintering at low temp. by adding a resin containing an organometallic compd. containing at least one kind metal among Bi, In, V and Ca and an org. solvent, moreover, containing a terpenoid based carboxylic acid.

A rosin based resin containing the organometallic compd. such as Bi octylate containing one more than metal among Bi, In, V and Ca, the org. solvent such as α-terpineol and the terpenoid based carboxylic acid such as abietic acid is heated and mixed in a prescribed ratio to dissolve, and the binder composition for granulation containing 1-3wt. times solvent and 1×10-4 to 10-3mol/g organometallic compd. per resin content is obtained. And after subjecting α-Fe2O3 and Y2O3 to wet mixing with water, the mixture is calcined and pulverized to obtain a calcined powder having 0.5-2.0μm average grain size. Then 5-10wt.% binder for granulation is added to the calcined powder, and the prepared powder is subjected to pressure molding, and after by subjecting the formed body to desolvating, the formed body is burned at about 900-1450°C in an oxygen atmosphere to obtain a ceramic such as garnet ferrite.