PROBLEM TO BE SOLVED: To provide a sealing implement for waterproofing, which can be easily attached irrespective of repeated operations, which makes waterproofing perfect, which gives consideration even to drainage and which is used, for example, for a more excellent sealing part of an opening/closing window of a greenhouse, and a waterproof device using the sealing implement. SOLUTION: This sealing implement is composed of a channel-shaped or U-shaped opening a0, and an extended side a4 which is formed by extending either of both sides a1 and a3, constituting the opening, in the direction opposite to the opening. COPYRIGHT: (C)2005,JPO&NCIPI