A catheter (1; 2; 3; 4; 5; 60e, 111; 60g), comprising: a reinforcing body (30; 30a; 30b; 30c; 30d; 30e, 30f; 30g) that is formed by winding or weaving a wire (20; 20a; 20b, 21b; 20c; 20d, 21d; 20e, 20f; 20g) so that a gap (25; 25a; 25b; 25c; 25d; 25e, 25f; 25g) is provided between the adjacent wire; an inner layer (10; 10a; 10b; 10c; 10d; 10e, 10f; 10g) that covers an outer periphery of the reinforcing body (30; 30a; 30b; 30c; 30d; 30e, 30f; 30g); and an outer layer (40; 40a; 40b; 40c; 40d; 40e, 40f; 40g) that covers an outer periphery of the inner layer (10; 10a; 10b; 10c; 10d; 10e, 10f; 10g), wherein the reinforcing body (30; 30a; 30b; 30c; 30d; 30e, 30f; 30g) is formed integrally including a small diameter portion (31; 31a; 31b; 31c, 35c; 31d, 35d; 31e, 31f; 31g) with a first outer diameter (D1; D3; D5; D7; D9; D11, D13; D15), a large diameter portion (33; 33a; 33b; 33c; 33d; 33e, 33f; 33g) with a second outer diameter (D2; D4; D6; D8; D10; D12, D14; D16) larger than the first outer diameter (D1; D3; D5; D7; D9; D11, D13; D15), and a tapered portion (32; 32a; 32b; 32c; 32d; 32e, 32f; 32g) increasing in diameter from the small diameter portion (31; 31a; 31b; 31c, 35c; 31d, 35d; 31e, 31f; 31g) to the large diameter portion (33; 33a; 33b; 33c; 33d; 33e, 33f; 33g), and at least the large diameter portion (33; 33a; 33b; 33c; 33d; 33e, 33f; 33g) of the reinforcing body (30; 30a; 30b; 30c; 30d; 30e, 30f; 30g) is embedded in the outer layer (40; 40a; 40b; 40c; 40d; 40e, 40f; 40g), characterised in that the tapered portion (32; 32a; 32b; 32c; 32d; 32e, 32f; 32g) increases in diameter toward a distal end side, and the small diameter portion (31; 31a; 31b; 31c, 35c; 31d, 35d; 31e, 31f; 31g) is provided in the inner layer (10; 10a; 10b; 10c; 10d; 10e, 10f; 10g). a reinforcing body (30; 30a; 30b; 30c; 30d; 30e, 30f; 30g) that is formed by winding or weaving a wire (20; 20a; 20b, 21b; 20c; 20d, 21d; 20e, 20f; 20g) so that a gap (25; 25a; 25b; 25c; 25d; 25e, 25f; 25g) is provided between the adjacent wire; an inner layer (10; 10a; 10b; 10c; 10d; 10e, 10f; 10g) that covers an outer periphery of the reinforcing body (30; 30a; 30b; 30c; 30d; 30e, 30f; 30g); and an outer layer (40; 40a; 40b; 40c; 40d; 40e, 40f; 40g) that covers an outer periphery of the inner layer (10; 10a; 10b; 10c; 10d; 10e, 10f; 10g), wherein the reinforcing body (30; 30a; 30b; 30c; 30d; 30e, 30f; 30g) is formed integrally including a small diameter portion (31; 31a; 31b; 31c, 35c; 31d, 35d; 31e, 31f; 31g) with a first outer diameter (D1; D3; D5; D7; D9; D11, D13; D15), a large diameter portion (33; 33a; 33b; 33c; 33d; 33e, 33f; 33g) with a second outer diameter (D2; D4; D6; D8; D10; D12, D14; D16) larger than the first outer diameter (D1; D3; D5; D7; D9; D11, D13; D15), and a tapered portion (32; 32a; 32b; 32c; 32d; 32e, 32f; 32g) increasing in diameter from the small diameter portion (31; 31a; 31b; 31c, 35c; 31d, 35d; 31e, 31f; 31g) to the large diameter portion (33; 33a; 33b; 33c; 33d; 33e, 33f; 33g), and at least the large diameter portion (33; 33a; 33b; 33c; 33d; 33e, 33f; 33g) of the reinforcing body (30; 30a; 30b; 30c; 30d; 30e, 30f; 30g) is embedded in the outer layer (40; 40a; 40b; 40c; 40d; 40e, 40f; 40g), characterised in that the tapered portion (32; 32a; 32b; 32c; 32d; 32e, 32f; 32g) increases in diameter toward a distal end side, and the small diameter portion (31; 31a; 31b; 31c, 35c; 31d, 35d; 31e, 31f; 31g) is provided in the inner layer (10; 10a; 10b; 10c; 10d; 10e, 10f; 10g).