PROBLEM TO BE SOLVED: To provide a pest-controlling agent having high safeness to a human body and plants and an excellent pest-controlling effect and stability.SOLUTION: A pest-controlling agent comprises: monoglyceryl caprate; at least one compound selected from the group consisting of polyethyleneglycol fatty acid ester, sucrose fatty acid ester, polyglycerin fatty acid ester, polyoxyethylenesorbitan fatty acid ester and polyoxyethylene styrylphenylether; and water.