The present disclosure describes Cephem compounds of the formula:wherein,X is N, CH or C—Cl;T is S or the like;A and G are lower alkylene or the like;B is a single bond or the like;D is optionally present, and when present is, —NR7—, —CO—, —CO—NR7—, —NR7—CO—, —NR7—CO—NR7—, or the like;F is optionally present, and when present is or phenylene;R3 and R4 are —OR8;R5 and R6 each is independently hydrogen, halogen, nitrile, or —OR8;or an ester at the carboxyl at the 7-position side chain or at the 4-position, a compound protected at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof, which have a wide antimicrobial spectrum and have potent antimicrobial activity against beta-lactamase producing Gram negative bacteria.