PROBLEM TO BE SOLVED: To provide a new antibacterial means effective to various fungus involving pathogenic fungus and plant pathogenic filamentous fungus.SOLUTION: Provided is an antibacterial agent to fungus comprising cyano acrylate polymer particles including at least one kind selected from the group consisting of amino acid, an amino acid derivative, their oligomers and polymers, sugar and polysorbate, not including antibacterial active ingredients to fungus, and having the average particle diameter of below 1,000 nm as an active ingredient. The antibacterial agent is useful particularly as a control agent for plant diseases by filamentous fungus.
