A sealing device sealing a gap between a housing, and a rotary shaft which extends through said housing, the sealing device comprising: a seal member which is retained to said housing side; a sleeve member which is retained to said rotary shaft side and is made of a metal material; and a discoid protection ring which is retained to said seal member side, wherein said sleeve member is provided with an inner cylinder portion which is fitted to an outer peripheral surface of said rotary shaft, and a collar portion which extends to an outer side in a diametrical direction from one end in an axial direction of said inner cylinder portion, wherein said seal member is constructed by a reinforcing ring comprising a tubular portion which is fitted to said housing side, an inner collar-like portion which extends to an inner side in a diametrical direction from one end in an axial direction of said tubular portion, and an outer collar-like portion which extends to an outer side in the diametrical direction from the other end in the axial direction of said tubular portion, and made of a metal material, a radial lip portion which is integrally formed in said inner collar-like portion, is made of a rubber-like elastic material and comes into contact in a sealing manner with an outer peripheral surface of said inner cylinder portion, and an end face lip portion which comes into elastic contact with said collar portion, wherein said protection ring is structured such that an outer end portion in a diametrical direction is caulked and fixed by an end portion in a diametrical direction of said outer collar-like portion, and an inner end portion in a diametrical direction forms a tubular folded portion which extends toward said collar portion, and wherein said collar portion of said sleeve member forms a first dust lip which comes into elastic contact with an inner peripheral surface of said tubular folded portion and is made of a rubber-like elastic material, a second dust lip which comes into elastic contact with an inner side surface of said protection ring and is made of a rubber-like elastic material, characterized in that said collar portion comprises a plurality of annular projections which are faced to a leading end portion of said tubular folded portion in a contactable manner, are provided in a surface of said collar portion and are made of a rubber-like elastic material. a seal member which is retained to said housing side; a sleeve member which is retained to said rotary shaft side and is made of a metal material; and a discoid protection ring which is retained to said seal member side, wherein said sleeve member is provided with an inner cylinder portion which is fitted to an outer peripheral surface of said rotary shaft, and a collar portion which extends to an outer side in a diametrical direction from one end in an axial direction of said inner cylinder portion, wherein said seal member is constructed by a reinforcing ring comprising a tubular portion which is fitted to said housing side, an inner collar-like portion which extends to an inner side in a diametrical direction from one end in an axial direction of said tubular portion, and an outer collar-like portion which extends to an outer side in the diametrical direction from the other end in the axial direction of said tubular portion, and made of a metal material, a radial lip portion which is integrally formed in said inner collar-like portion, is made of a rubber-like elastic material and comes into contact in a sealing manner with an outer peripheral surface of said inner cylinder portion, and an end face lip portion which comes into elastic contact with said collar portion, wherein said protection ring is structured such that an outer end portion in a diametrical direction is caulked and fixed by an end portion in a diametrical direction of said outer collar-like portion, and an inner end portion in a diametrical direction forms a tubular folded portion which extends toward said collar portion, and wherein said collar portion of said sleeve member forms a first dust lip which comes into elastic contact with an inner peripheral surface of said tubular folded portion and is made of a rubber-like elastic material, a second dust lip which comes into elastic contact with an inner side surface of said protection ring and is made of a rubber-like elastic material, characterized in that said collar portion comprises a plurality of annular projections which are faced to a leading end portion of said tubular folded portion in a contactable manner, are provided in a surface of said collar portion and are made of a rubber-like elastic material.