A centrifugal fan comprising: a main plate having a rotation center; and a plurality of blades extending from the main plate in a direction of a rotation axis passing the rotation center, wherein the plurality of blades include, at least partially, an arrangement in which intervals between the adjacent blades are unequal intervals, a length direction of each blade extends from an inner circumferential side to an outer circumferential side of the main plate, and in a pair of the blades (4_1, 4_2) adjacent to each other with a smallest interval in a rotation direction among the plurality of blades, the blade (4_2) positioned on a backward side in the rotation direction and the blade (4_1) positioned on a forward side in the rotation direction are different in outer-circumferential-side shapes, and an action of discharging a fluid toward the outer circumferential side by the blade (4_2) positioned on the backward side in the rotation direction is made smaller as compared to the blade (4_1) positioned on the forward side in the rotation direction, characterized in that in the pair of blades (4_1, 4_2) adjacent to each other with the smallest interval in the rotation direction among the plurality of blades, each blade of the pair of blades (4_1, 4_2) has a first part (Fin) extending from an inner circumferential side toward an outer circumferential side of the blade and formed in a concave shape with respect to the rotation direction, and a second part (Fout) extending from the first part (Fin) toward an outer circumferential side and formed in a convex shape with respect to the rotation direction, and a warp radius of the second part (Fout) of the blade (4_2) positioned on the backward side in the rotation direction is smaller than a warp radius of the second part (Fout) of the blade (4_1) positioned on the forward side in the rotation direction. a main plate having a rotation center; and a plurality of blades extending from the main plate in a direction of a rotation axis passing the rotation center, wherein the plurality of blades include, at least partially, an arrangement in which intervals between the adjacent blades are unequal intervals, a length direction of each blade extends from an inner circumferential side to an outer circumferential side of the main plate, and in a pair of the blades (4_1, 4_2) adjacent to each other with a smallest interval in a rotation direction among the plurality of blades, the blade (4_2) positioned on a backward side in the rotation direction and the blade (4_1) positioned on a forward side in the rotation direction are different in outer-circumferential-side shapes, and an action of discharging a fluid toward the outer circumferential side by the blade (4_2) positioned on the backward side in the rotation direction is made smaller as compared to the blade (4_1) positioned on the forward side in the rotation direction, characterized in that in the pair of blades (4_1, 4_2) adjacent to each other with the smallest interval in the rotation direction among the plurality of blades, each blade of the pair of blades (4_1, 4_2) has a first part (Fin) extending from an inner circumferential side toward an outer circumferential side of the blade and formed in a concave shape with respect to the rotation direction, and a second part (Fout) extending from the first part (Fin) toward an outer circumferential side and formed in a convex shape with respect to the rotation direction, and a warp radius of the second part (Fout) of the blade (4_2) positioned on the backward side in the rotation direction is smaller than a warp radius of the second part (Fout) of the blade (4_1) positioned on the forward side in the rotation direction.