PROBLEM TO BE SOLVED: To provide a novel active ingredient that has excellent controlling effect on microorganism such as bacterium, mold, yeast, algae and the like and to provide a bactericidal composition for industrial use that contains the active ingredient.SOLUTION: A chalcone compound having a substituent at a specific position or a salt thereof has excellent controlling effect on microorganism such as bacterium, mold, yeast, algae and the like.COPYRIGHT: (C)2014,JPO&INPIT【課題】細菌、カビ、酵母、藻等の微生物に対し優れた防除効果を有する新規な有効成分、及びそれを含有する工業用殺菌組成物を提供すること。【解決手段】特定の位置に置換基を有するカルコン系化合物又はその塩が、細菌、カビ、酵母、藻等の微生物に対し優れた防除効果を有することを見出した。【選択図】なし