To make easily attachable and detachable a sealing-up device while maintaining sealing performance in the sealing-up device arranged between two opposite faces by providing a seal lip pair respectively abutting on the two opposite faces, a holding part connecting together the seal lip pair, and an annular member giving energizing force to the lips of the seal lip pair.

This sealing device 1 seals an annular gap 4 between the shaft hole 2a of a housing 2 and the outer circumferential face 3a of a shaft 3 as the two opposite faces, main seal lips 5, 6 as seal lip pair, and assistant seal lip pair functioning also as a holding part on the atmosphere side 0 in the axial direction of the main seal lips 5, 6, are integrally provided, and a connecting part 9 connects together between the main seal lips 5, 6. A coil spring 12 abuts on the pressure receiving part 11b of a groove 11 on the assistant seal lips 7, 8 side to give energizing force from the back sides of the respective seal lips 5-8 so as to raise the contact face pressure of the seal lips 5-8.