PROBLEM TO BE SOLVED: To provide polypeptide having excellent antibacterial activity.SOLUTION: The present invention provides polypeptide comprising a specific amino acid sequence, polypeptide of which the carboxyl-terminal is amidated, or polypeptide of which the amino-terminal is acetylated. The prevention also provides an antibacterial agent, an antifungal agent or an antiseptic containing as an effective ingredient the polypeptide, and use of the polypeptide for the prevention, amelioration or treatment of diseases such as burn, decubitus, wound, skin ulcer, leg ulcer, diabetic ulcer, occlusive arterial disease and arteriosclerosis obliterans, cellulitis, acute lymphangitis, lymphadenitis, erysipelas, skin abscess, necrotizing subcutaneous infection, staphylococcal scalded skin syndrome (SSSS), folliculitis, facial furuncle, suppurative hidradenitis, carbuncle, infectious paronychia, erythrasma and severe infection (sepsis).【課題】優れた抗菌活性を有するポリペプチドの提供。【解決手段】特定のアミノ酸配列からなるポリペプチド、前記ポリペプチドでカルボキシル末端がアミド化されているポリペプチド、アミノ末端がアセチル化されているポリペプチド。前記ポリペプチドを有効成分とする抗菌剤、抗真菌剤または消毒剤、及び熱傷、褥瘡、創傷、皮膚潰瘍、下肢潰瘍、糖尿病性潰瘍、閉塞性動脈疾患及び閉塞性動脈硬化症、蜂巣炎、急性リンパ管炎、リンパ節炎、丹毒、皮膚膿瘍、壊死性皮下感染、ブドウ球菌性熱傷様皮膚症候群（ＳＳＳＳ）、毛包炎、フルンケル（面疔）、化膿性汗腺炎、カルブンケル（癰）、感染性爪囲炎、紅色陰癬及び重症感染症（敗血症）等の疾患の予防、改善又は治療への前記ポリペプチドの使用。【選択図】なし
