A sealing structure includes a sealing device including a first seal lip having a first seal-lip end, and a support ring that supports the first seal lip; and a plurality of members that define an attachment space into which the sealing device is attached, the members including an inner peripheral wall arranged on the inner periphery side of the sealing device, a first end wall arranged on one axial end of the sealing device, and a second end wall arranged on another axial end of the sealing device. The first seal-lip end has a certain amount of interference with the inner peripheral wall and the first end wall so that its radial reaction force radially presses the support ring outward and its axial reaction force presses the support ring toward the second end wall.