A process for preparing a 3-halogenomethylcephem compound of the formula (2) or a salt thereof <;CHEM>; wherein X<;1>; is a halogen atom, characterized in that a carboxylic acid protecting group at the 4-position of a 7-amino-3-halogenomethylcephem compound of the formula (1) or a salt thereof <;CHEM>; wherein X<;1>; is a halogen atom, and R<;1>; is a benzyl group which has on a phenyl ring an electron-donating group as a substituent, or a diphenylmethyl group which may have an electron-donating group on a phenyl ring, is deprotected with a phenol derivative.