PROBLEM TO BE SOLVED : To obtain the subject bactericide excellent in bactericidal actions on enterohemorrhagic Escherichia coli O-157 : H7, comprising an extract of asparagus as an active ingredient. SOLUTION : This bactericide comprises an extract of asparagus as an active ingredient. The extract of asparagus is obtained by grinding asparagus to give a ground material, mixing the ground material with a solvent (e.g. water) at <80°C to prepare a solution having ≥5 wt.% concentration and a supernatant liquid of the solution. The bactericide sterilizes O-157 of 107 order to ≤10 in 48 hours in an experiment for repeatedly examining sterilizing effects based on the examination method data of national medical health insurance section) of enterohemorrhagic Escherichia coli O-157 by a guide of niigata prefectural research laboratory for health and environment.