A sealing apparatus comprising: an annular reinforcing ring centered about an axis (x); and an annular elastic body part comprising a seal lip, attached to the reinforcing ring, made of elastomer, and centered about the axis (x), wherein the seal lip comprises a lip tip portion projecting toward an inner periphery side (d) and defined by an annular sealing side surface on a sealed object side (b) and an annular atmospheric side surface on a non-sealed object side (a), the sealing side surface and the atmospheric side surface are connected through a lip tip, the lip tip portion comprises a circumferential projection and a screw portion capable of forming an airflow flowing toward the sealed object side (b), on the atmospheric side surface, the screw portion comprises a plurality of sealed object side (b) screw projections obliquely extending with respect to the lip tip and projecting from the atmospheric side surface; and a plurality of non-sealed object side (a) screw projections obliquely extending with respect to the lip tip and projecting from the atmospheric side surface, the circumferential projection annularly projects from the atmospheric side surface to the inner periphery side (d) and extends parallel to the lip tip, and the circumferential projection has a height from the atmospheric side surface less than the height (h2, h3) of each of the sealed object side (b) screw projections and the non-sealed object side (a) screw projections from the atmospheric side surface, and the sealed object side (b) screw projections extend between the lip tip and the circumferential projection and are arranged at equal pitch intervals in parallel with each other, the non-sealed object side (a) screw projections extend from the circumferential projection to the non-sealed object side (a) and are arranged at equal pitch intervals in parallel with each other, and each of the non-sealed object side (a) screw projections does not overlap the adjacent non-sealed object side (a) screw projections in a direction of the axis (x) with each other, wherein the non-sealed object side (a) screw projections have a pitch greater than the pitch of the sealed object side (b) screw projections. an annular reinforcing ring centered about an axis (x); and an annular elastic body part comprising a seal lip, attached to the reinforcing ring, made of elastomer, and centered about the axis (x), wherein the seal lip comprises a lip tip portion projecting toward an inner periphery side (d) and defined by an annular sealing side surface on a sealed object side (b) and an annular atmospheric side surface on a non-sealed object side (a), the sealing side surface and the atmospheric side surface are connected through a lip tip, the lip tip portion comprises a circumferential projection and a screw portion capable of forming an airflow flowing toward the sealed object side (b), on the atmospheric side surface, the screw portion comprises a plurality of sealed object side (b) screw projections obliquely extending with respect to the lip tip and projecting from the atmospheric side surface; and a plurality of non-sealed object side (a) screw projections obliquely extending with respect to the lip tip and projecting from the atmospheric side surface, the circumferential projection annularly projects from the atmospheric side surface to the inner periphery side (d) and extends parallel to the lip tip, and the circumferential projection has a height from the atmospheric side surface less than the height (h2, h3) of each of the sealed object side (b) screw projections and the non-sealed object side (a) screw projections from the atmospheric side surface, and the sealed object side (b) screw projections extend between the lip tip and the circumferential projection and are arranged at equal pitch intervals in parallel with each other, the non-sealed object side (a) screw projections extend from the circumferential projection to the non-sealed object side (a) and are arranged at equal pitch intervals in parallel with each other, and each of the non-sealed object side (a) screw projections does not overlap the adjacent non-sealed object side (a) screw projections in a direction of the axis (x) with each other, wherein the non-sealed object side (a) screw projections have a pitch greater than the pitch of the sealed object side (b) screw projections.