A cross-flow fan comprising a blade wheel, the blade wheel including: a plurality of blades arranged in a circumferential direction centered on a predefined axis with randomly different intervals therebetween; and a support unit connected to said plurality of blades to support said blades in a unified manner, wherein a plurality of said blade wheels being stacked on each other along an axial direction of said predefined axis, an inner diameter d and an outer diameter D of said blades meet a relationship expressed by 0.55 ≤ d/D ≤ 0.95, N representing number of said blades, a chord length L of said blades, said outer diameter D of said blades, and M representing number of said blade wheels meet relationships expressed by 0.6 ≤ L/(πD/N) ≤ 2.8 and 0.15 ≤ πD/N × M) ≤ 3.77, the plurality of said blade wheels are stacked on each other in a manner that a displacement angle θ is generated within a range defined by (1.2 × 360°/(N × M)) ≤ θ ≤ (360°/N) between said blade wheels adjacent to each other when viewed from the axial direction of said predefined axis, and said displacement angle θ is defined such that the overlapping number of said blades having an equal installation angle in all of said blades is at most 5% of N × M representing a total number of said blades, characterized in that a relationship expressed by 0.05(πD/N) ≤ |Cn-(πD/N)| ≤ 0.24(πD/N) is met between arbitrary adjacent ones of said blades, where Cn (n = 1, 2,..., N-1, N) is a length of a circular arc centered on said predefined axis and connecting outer peripheral ends of said blades adjacent to each other on a plane orthogonal to said predefined axis. a plurality of blades arranged in a circumferential direction centered on a predefined axis with randomly different intervals therebetween; and a support unit connected to said plurality of blades to support said blades in a unified manner, wherein a plurality of said blade wheels being stacked on each other along an axial direction of said predefined axis, an inner diameter d and an outer diameter D of said blades meet a relationship expressed by 0.55 ≤ d/D ≤ 0.95, N representing number of said blades, a chord length L of said blades, said outer diameter D of said blades, and M representing number of said blade wheels meet relationships expressed by 0.6 ≤ L/(πD/N) ≤ 2.8 and 0.15 ≤ πD/N × M) ≤ 3.77, the plurality of said blade wheels are stacked on each other in a manner that a displacement angle θ is generated within a range defined by (1.2 × 360°/(N × M)) ≤ θ ≤ (360°/N) between said blade wheels adjacent to each other when viewed from the axial direction of said predefined axis, and said displacement angle θ is defined such that the overlapping number of said blades having an equal installation angle in all of said blades is at most 5% of N × M representing a total number of said blades, characterized in that a relationship expressed by 0.05(πD/N) ≤ |Cn-(πD/N)| ≤ 0.24(πD/N) is met between arbitrary adjacent ones of said blades, where Cn (n = 1, 2,..., N-1, N) is a length of a circular arc centered on said predefined axis and connecting outer peripheral ends of said blades adjacent to each other on a plane orthogonal to said predefined axis.