A sealing arrangement comprising a rubber gasket of annular shape and two objective members (2, 3) to be sealed and fastened to each other with said rubber gasket interposed therebetween, wherein: one of said two objective members to be sealed has a step-shaped portion of which inside is opened by a step-floor portion and an inner circumferential wall portion perpendicular to said step-floor portion, the step-floor portion including one seal line portion, whereas the other member of said two objective members has a flat-shaped portion parallel to said step-floor portion and including another seal line portion; said rubber gasket comprises an integrally molded body made of elastomer having a cylindrical body, a flange-shaped portion, and an annular core member, said cylindrical body being interposed in said step-shaped portion, said flange-shaped portion extending outward from one end of said cylindrical body in axial direction along an entire outer circumferential surface, said annular core member being embedded in said flange-shaped portion along an entire circumference; and said rubber gasket is constructed such that when said two objective members (2, 3) to be sealed are fastened with said rubber gasket interposed therebetween, both ends of said cylindrical body in axial direction thereof are positioned respectively at the seal line portions (2L, 3L) of said two objective members (2, 3) to be sealed, said cylindrical body is compressed by fastening force along fastening direction, and said flange-shaped portion is positioned outside said seal line portions (2L, 3L) in diametrical direction, said sealing arrangement being characterised in that said cylindrical body has no said annular core member therein and is made solely of elastomer, and in that said flange-shaped portion is interposed in a gap formed between said two objective members (2, 3) to be sealed. one of said two objective members to be sealed has a step-shaped portion of which inside is opened by a step-floor portion and an inner circumferential wall portion perpendicular to said step-floor portion, the step-floor portion including one seal line portion, whereas the other member of said two objective members has a flat-shaped portion parallel to said step-floor portion and including another seal line portion; said rubber gasket comprises an integrally molded body made of elastomer having a cylindrical body, a flange-shaped portion, and an annular core member, said cylindrical body being interposed in said step-shaped portion, said flange-shaped portion extending outward from one end of said cylindrical body in axial direction along an entire outer circumferential surface, said annular core member being embedded in said flange-shaped portion along an entire circumference; and said rubber gasket is constructed such that when said two objective members (2, 3) to be sealed are fastened with said rubber gasket interposed therebetween, both ends of said cylindrical body in axial direction thereof are positioned respectively at the seal line portions (2L, 3L) of said two objective members (2, 3) to be sealed, said cylindrical body is compressed by fastening force along fastening direction, and said flange-shaped portion is positioned outside said seal line portions (2L, 3L) in diametrical direction, said sealing arrangement being characterised in that said cylindrical body has no said annular core member therein and is made solely of elastomer, and in that said flange-shaped portion is interposed in a gap formed between said two objective members (2, 3) to be sealed.