A sealing mechanism includes a pair of space forming rings which face each other and are configured for surrounding a shaft body, an outer bellows-joint having one end connected to an outer periphery of one of the space forming rings and another end connected to an outer periphery of the other of the space forming rings, and an inner bellows-joint having one end connected to an inner periphery of one of the space forming rings and another end connected to an inner periphery of the other of the space forming rings. Each of the inner bellows-joint and the outer bellows-joint is a corrugated plate. The space forming rings space the inner bellows-joint and the outer bellows-joint apart from each other such that the inner bellows-joint and the outer bellows-joint do not come in contact with each other.