A diffractive multi-focal intraocular or contact lens having a diffractive structure comprising a plurality of zones in a concentric circle form, characterized in that: the diffractive structure includes an overlapping region in which at least two zone profiles are overlapped on the same region and the overlapping region is across the entire lens optical region; at the overlapping region, at least a portion of a first zone profile of the at least two zone profiles has a zone pitch expressed by Equation 1, and at least a portion of a second zone profile of the at least two zone profiles has a zone pitch expressed by Equation 2, and an addition power P 1 given by the first zone profile and an addition power P 2 given by the second zone profile are determined by a relational expression of Equation 3, where a and b are mutually different integers of greater than zero, while quotients when a and b are divided by a mutual greatest common divisor thereof are both an integer other than 1, and a value of a/b is a value that cannot be expressed by a natural number X or by 1/X, and wherein the diffractive multi-focal intraocular or contact lens is able to generate at least three focal points; and wherein the diffractive multi-focal intraocular or contact lens is an ophthalmic lens for which of the three focal points, one focal point is used for far vision, and another focal point is used for near vision, and the other focal point is used for intermediate vision; and wherein the focal point for far vision is given by a Oth order diffracted light of the diffractive structure, and the focal point for near vision and the focal point for intermediate vision are given by a +1 order diffracted light by the first zone profile and the second zone profile. r n = r 1 2 + 2 λ n − 1 P 1 λ: Design wavelength r n: nth zone radius of the first zone profile r 1: First zone radius of the first zone profile P 1: Addition power of the first zone profile n: Natural number r m = r 1 ′ 2 + 2 λ m − 1 P 2 λ: Design wavelength r m: mth zone radius of the second zone profile r 1 ': First zone radius of the second zone profile P 2: Addition power of the second zone profile m: Natural number P 2 = a b × P 1 the diffractive structure includes an overlapping region in which at least two zone profiles are overlapped on the same region and the overlapping region is across the entire lens optical region; at the overlapping region, at least a portion of a first zone profile of the at least two zone profiles has a zone pitch expressed by Equation 1, and at least a portion of a second zone profile of the at least two zone profiles has a zone pitch expressed by Equation 2, and an addition power P 1 given by the first zone profile and an addition power P 2 given by the second zone profile are determined by a relational expression of Equation 3, where a and b are mutually different integers of greater than zero, while quotients when a and b are divided by a mutual greatest common divisor thereof are both an integer other than 1, and a value of a/b is a value that cannot be expressed by a natural number X or by 1/X, and wherein the diffractive multi-focal intraocular or contact lens is able to generate at least three focal points; and wherein the diffractive multi-focal intraocular or contact lens is an ophthalmic lens for which of the three focal points, one focal point is used for far vision, and another focal point is used for near vision, and the other focal point is used for intermediate vision; and wherein the focal point for far vision is given by a Oth order diffracted light of the diffractive structure, and the focal point for near vision and the focal point for intermediate vision are given by a +1 order diffracted light by the first zone profile and the second zone profile. r n = r 1 2 + 2 λ n − 1 P 1 λ: Design wavelength r n: nth zone radius of the first zone profile r 1: First zone radius of the first zone profile P 1: Addition power of the first zone profile n: Natural number r m = r 1 ′ 2 + 2 λ m − 1 P 2 λ: Design wavelength r m: mth zone radius of the second zone profile r 1 ': First zone radius of the second zone profile P 2: Addition power of the second zone profile m: Natural number P 2 = a b × P 1