Abstract: An improved process for the preparation of an antibiotic substance, more specifically 7{[2-(2-aminothiazol-4-yl)-2-synmethoxyimino]acetamido}-3-{[(2,5-dihydro-6 -hydroxy-2-methyl-5-oxo-1,2,4-triazin-3-yl)thio]methyl}-3-cephem-4-carboxyl ic acid in the form of disodium salt hemieptahydrate is described, where 7-amino-3-{[(2,5-dihydro-6-hydroxy-2-methyl-5-oxo-1,2,4-triazin-3-yl)thio] methyl}-3-cephem-4-carboxylic acid is made to react with 2-mercaptobenzothiazole 2-(2-aminothiazol-4-yl)-2-syn-methoxyiminoacetate in an aqueous solution in suitable solvents, in the presence of an amine selected from the group consisting of trimethylamine, triethylamine, 1,4-dimethylpiperazine, N-ethylpiperidine, pyridine and dimethylaminopyridine and the obtained aqueous solution is treated with a base selected from the group consisting of dicyclohexylamine, diphenylamine, diisopropylamine, N-tert-butylcyclohexylamine and N,N-dibenzylethylendiamine, in a suitable form, and the thus formed precipitate is reacted in suitable solven