A fluid mixing output apparatus (S, 1100, 2100, 3100) comprising: a housing (110, 210, 310); and an internal structure (140, 240, 340) accommodated in the housing (110, 210, 310), wherein the housing (110, 210, 310) is provided with a plurality of fluid supply ports (111-1, 111-2, 211-1, 211-2a~211-2c, 213-I, 311-2a~311-2d, 313-I) for supplying at least a first fluid and a second fluid and a fluid outlet (112, 212-0, 312-0) at its downstream end for outputting a plurality of fluids after mixing the plurality of fluids, and the internal structure (140, 240, 340) comprises a first portion (143, 243, 343), a second portion (145, 245, 345), a third portion (147, 247, 347), and a fourth portion (149, 249, 349), wherein the first portion (143, 243, 343) comprises a shaft portion (141, 241, 341) and a vane spirally formed to generate a swirling flow in a fluid, the second portion (145, 245, 345) is located downstream from the first portion (143, 243, 343), and comprises a shaft portion (141, 241, 341) and a plurality of protrusions (145p, 245p, 345p) protruding from an outer circumferential surface of the shaft portion, the third portion (147, 247, 347) is located downstream from the second portion (145, 245, 345), and comprises a shaft portion (141, 241, 341) and a vane spirally formed to generate a swirling flow in a fluid, and the fourth portion (149, 249, 349) is located downstream from the third portion (147, 247, 347), and comprises a shaft portion (141, 241, 341) and a plurality of protrusions (149p, 249p, 349p) protruding from an outer circumferential surface of the shaft portion, and characterized in that one of the plurality of fluid supply ports of the housing (110, 210, 310) is formed by opening an upstream end (213-I, 313-I) and/or in a portion corresponding to the vane of the first portion (111-1, 211-1, 211-1), and at least the first fluid is supplied to the first portion (143, 243, 343) and supplied to the second portion (145, 245, 345) as a swirling flow, and that one of the plurality of fluid supply ports (211-2a-211-2c, 311-2a-311-2d) of the housing (110, 210, 310) is formed in a portion corresponding to the vane of the third portion (147, 247, 347), and the second fluid is supplied to the third portion (147, 247, 347) and supplied to the fourth portion (149, 249, 349) as a swirling flow while being mixed with at least the first fluid. a housing (110, 210, 310); and an internal structure (140, 240, 340) accommodated in the housing (110, 210, 310), wherein the housing (110, 210, 310) is provided with a plurality of fluid supply ports (111-1, 111-2, 211-1, 211-2a~211-2c, 213-I, 311-2a~311-2d, 313-I) for supplying at least a first fluid and a second fluid and a fluid outlet (112, 212-0, 312-0) at its downstream end for outputting a plurality of fluids after mixing the plurality of fluids, and the internal structure (140, 240, 340) comprises a first portion (143, 243, 343), a second portion (145, 245, 345), a third portion (147, 247, 347), and a fourth portion (149, 249, 349), wherein the first portion (143, 243, 343) comprises a shaft portion (141, 241, 341) and a vane spirally formed to generate a swirling flow in a fluid, the second portion (145, 245, 345) is located downstream from the first portion (143, 243, 343), and comprises a shaft portion (141, 241, 341) and a plurality of protrusions (145p, 245p, 345p) protruding from an outer circumferential surface of the shaft portion, the third portion (147, 247, 347) is located downstream from the second portion (145, 245, 345), and comprises a shaft portion (141, 241, 341) and a vane spirally formed to generate a swirling flow in a fluid, and the fourth portion (149, 249, 349) is located downstream from the third portion (147, 247, 347), and comprises a shaft portion (141, 241, 341) and a plurality of protrusions (149p, 249p, 349p) protruding from an outer circumferential surface of the shaft portion, and characterized in that one of the plurality of fluid supply ports of the housing (110, 210, 310) is formed by opening an upstream end (213-I, 313-I) and/or in a portion corresponding to the vane of the first portion (111-1, 211-1, 211-1), and at least the first fluid is supplied to the first portion (143, 243, 343) and supplied to the second portion (145, 245, 345) as a swirling flow, and that one of the plurality of fluid supply ports (211-2a-211-2c, 311-2a-311-2d) of the housing (110, 210, 310) is formed in a portion corresponding to the vane of the third portion (147, 247, 347), and the second fluid is supplied to the third portion (147, 247, 347) and supplied to the fourth portion (149, 249, 349) as a swirling flow while being mixed with at least the first fluid.