The method of producing a lyophilized preparation containing amorphous sodium salt of 6-fluoro-3-hydroxy-2-pyrazine carboxamide in the present invention is useful in producing a uniform quality of lyophilized preparation.本發明之包含6-氟-3-羥基-2-吡甲醯胺(6-fluoro-3-hydroxy-2-pyrazine carboxamide)之鈉鹽之非晶質的冷凍乾燥製劑之製造方法,作為製造均勻品質之冷凍乾燥製劑的方法係為有用。