A cephem compound represented by general formula (1), which has an excellent antibacterial effect against various pathogenic bacteria, wherein Q represents CH or N; R1 represents carboxylate, etc.; R represents group (a) or (b); R3 represents -(CH¿2?)m-Y (m being an integer of 1 to 5, and Y being quaternary ammonium), etc.; n represents an integer of 0,1 to 4; B?-¿ represents an anion; f represents 0 or 1 when R1 represents carboxylate, and 2 when R1 represents carboxyl; and ring C represents a five-membered heterocyclic group which bears four or less nitrogen atoms and may be substituted by lower alkyl.