To provide a stopper with a dust cover having a structure for improving workability at assembly in which a detent projection which is projected to the outer peripheral surface of the upper end in the axial direction of a rubber block is locked in a engaging peripheral groove formed on the inner surface of the peripheral wall of a retaining metal fitting, while securing extraction resistance force after assembling a rubber block.

While a detent projection 42 of a rubber block 12 is constructed by five divided projections 44 which are separately positioned in approximately equally segments in a peripheral direction, the peripheral length of respectively divided projections is set shorter than a peripheral separation of an adjacent divided protrusion 44.