An object of the present invention is to provide a gasket capable of improving cooling efficiency with a simpler configuration while keeping performance of the gasket and a manufacturing method thereof. A gasket includes a first annular portion which is formed by a metal wire woven fabric obtained by weaving a first metal wire and includes a seal target hole and a main body portion which is in contact with an outer peripheral edge of the first annular portion, in which the first metal wire forming the first annular portion and the first metal wire forming the main body portion are entangled with each other and a second metal wire is woven together with the first metal wire forming the first annular portion to form the first annular portion as a high thermal conduction region.