The synthesis and anti-Helicobacter pylori activity of a novel cephem derivative FR182024 (1) are described. FR182024 having a (5-methyl-1, 3, 4-thiadiazol-2-yl)-thio moiety at the 3- position and a phenylacetamido at the 7-position was found to have extremely potent in vitro anti-H. pylori activity, superior therapeutic efficacy to AMPC and CAM, and low potential for causing diarrhea.