<p>A rotation shaft seal provided with a seal member (2) of rubber having a short cylinder portion (27) gradually extending in diameter from a bent bottom portion (24a) to a fluid storing chamber (8) side to increase contact pressure of a bent root portion (34) of a seal element (3) to a rotation shaft (7) by pressing from the bent bottom portion (24a). Further, slightly leaked fluid on the seal element (3) side works as lubricant with an R-shaped curve formed on a lip end portion (22) of rubber sliding on the rotation shaft (7). <IMAGE></p>
