A rotor for a wind or water power machine, the rotor (1A, 1B) comprising a hub (10A, 10B), supported by a main shaft, and a blade (20A, 20B), a root end (21A, 21B) of the blade (20A, 20B) being connected to the hub (10A, 10B), wherein in a projection plane perpendicular to a central axis of rotation of the rotor (1A, 1B), at least a portion of a leading edge (31A, 31B) of the blade (20A, 20B) protrudes forward in a rotational direction of the rotor (1A, 1B) with respect to a first line segment (L1A, L1B) connecting an inward end (33A, 33B) of the leading edge (31A, 31B) in a radial direction of the rotor (1A, 1B) and an outward end (35A, 35B) of the leading edge (31A, 31B) in the radial direction of the rotor (1A, 1B), at least a portion of a section (34A, 34B) of the leading edge (31A, 31B) of the blade (20A, 20B) extending from the inward end (33A, 33B) of the leading edge (31A, 31B) in the radial direction of the rotor (1A,1B) to a tip (32A, 32B) of a leading edge (31A, 31B) protrusion is curved or bent to be convex forward in the rotational direction of the rotor (1A, 1B) with respect to a second line segment (L2A, L2B) connecting the inward end (33A, 33B) of the leading edge (31A, 31B) in the radial direction of the rotor (1A, 1B) and the tip (32A, 32B) of the leading edge (31A, 31B) protrusion, and at least a portion of a section (37A, 37B) of the leading edge (31A, 31B) of the blade (20A, 20B) extending from the tip (32A, 32B) of the leading edge (31A, 31B) protrusion to the outward end (35A, 35B) of the leading edge (31A, 31B) in the radial direction of the rotor (1A, 1B) protrudes backward in the rotational direction of the rotor (1A,1B) with respect to a fifth line segment (L5A, L5B) connecting the tip (32A, 32B) of the leading edge (31A, 31B) protrusion and the outward end (35A, 35B) of the leading edge (31A, 31B) in the radial direction of the rotor (1A, 1B), characterized in that an entire portion of a trailing edge (41A, 41B) of the blade (20A, 20B) protrudes forward in the rotational direction of the rotor (1A, 1B) with respect to a third line segment (L3A, L3B) connecting an inward end (43A, 43B) of the trailing edge (41A, 41B) in the radial direction of the rotor (1A, 1B) and an outward end (45A, 45B) of the trailing edge (41A, 41B) in the radial direction of the rotor (1A, 1B). at least a portion of a leading edge (31A, 31B) of the blade (20A, 20B) protrudes forward in a rotational direction of the rotor (1A, 1B) with respect to a first line segment (L1A, L1B) connecting an inward end (33A, 33B) of the leading edge (31A, 31B) in a radial direction of the rotor (1A, 1B) and an outward end (35A, 35B) of the leading edge (31A, 31B) in the radial direction of the rotor (1A, 1B), at least a portion of a section (34A, 34B) of the leading edge (31A, 31B) of the blade (20A, 20B) extending from the inward end (33A, 33B) of the leading edge (31A, 31B) in the radial direction of the rotor (1A,1B) to a tip (32A, 32B) of a leading edge (31A, 31B) protrusion is curved or bent to be convex forward in the rotational direction of the rotor (1A, 1B) with respect to a second line segment (L2A, L2B) connecting the inward end (33A, 33B) of the leading edge (31A, 31B) in the radial direction of the rotor (1A, 1B) and the tip (32A, 32B) of the leading edge (31A, 31B) protrusion, and at least a portion of a section (37A, 37B) of the leading edge (31A, 31B) of the blade (20A, 20B) extending from the tip (32A, 32B) of the leading edge (31A, 31B) protrusion to the outward end (35A, 35B) of the leading edge (31A, 31B) in the radial direction of the rotor (1A, 1B) protrudes backward in the rotational direction of the rotor (1A,1B) with respect to a fifth line segment (L5A, L5B) connecting the tip (32A, 32B) of the leading edge (31A, 31B) protrusion and the outward end (35A, 35B) of the leading edge (31A, 31B) in the radial direction of the rotor (1A, 1B), characterized in that