A rotating electrical machine comprising: a core including an annular yoke portion disposed while being centered around a rotation axis; a plurality of toothed portions that protrude from the yoke portion in a radial direction; and a tooth flange portion that circumferentially sticks out from a protruding end of each of the plurality of toothed portions while being centered around the rotation axis; and an insulator that covers a region from the toothed portion to the tooth flange portion, wherein the insulator includes a tooth cover portion which is disposed at a position to cover the outer circumference of the toothed portion, and around which a coil strand is wound, and a flange cover portion which is disposed at a position to cover the tooth flange portion, and wherein reinforced portions are formed at the boundary between the tooth cover portion and the flange cover portion, and includes a first restricting surface (Ra) which comes into contact with a coil strand positioned in an end portion of a predetermined layer from multiple layers of the coil strand wound around the outer circumference of the tooth cover portion, and a second restricting surface (Rb) which is gently inclined compared to the first restricting surface so as to enlarge a winding region of a layer of the coil strand wound over the predetermined layer, and characterized in that a first layer, a second layer, and a third layer are formed in the winding region, the first layer of the coil strand is wound starting from the position of a base end adjacent to the yoke portion to a location in which a winding position reaches the first restricting surface, the second layer of the coil strand is wound from the first restricting surface to a location in which a winding position reaches the position of the base end, while overlapping the first layer, and the third layer of the coil strand is wound from the position of the base end to a location in which a winding position reaches the second restricting surface, while overlapping the second layer, and the predetermined layer is the second layer, and wherein the reinforced portions are respectively formed in portions of the insulator adjacent to a flange cover wall and a tip end wall, and one of the reinforced portions is formed by setting the thickness of a portion adjacent to the vertical surface cover wall of the flange cover wall to be greater than those of other portions of the flange cover wall, and the other of the reinforced portions is formed by setting the thickness of a portion adjacent to the horizontal surface cover wall of the tip end wall to be greater than those of other portions of the tip end wall. a core including an annular yoke portion disposed while being centered around a rotation axis; a plurality of toothed portions that protrude from the yoke portion in a radial direction; and a tooth flange portion that circumferentially sticks out from a protruding end of each of the plurality of toothed portions while being centered around the rotation axis; and an insulator that covers a region from the toothed portion to the tooth flange portion, wherein the insulator includes a tooth cover portion which is disposed at a position to cover the outer circumference of the toothed portion, and around which a coil strand is wound, and a flange cover portion which is disposed at a position to cover the tooth flange portion, and wherein reinforced portions are formed at the boundary between the tooth cover portion and the flange cover portion, and includes a first restricting surface (Ra) which comes into contact with a coil strand positioned in an end portion of a predetermined layer from multiple layers of the coil strand wound around the outer circumference of the tooth cover portion, and a second restricting surface (Rb) which is gently inclined compared to the first restricting surface so as to enlarge a winding region of a layer of the coil strand wound over the predetermined layer, and characterized in that a first layer, a second layer, and a third layer are formed in the winding region, the first layer of the coil strand is wound starting from the position of a base end adjacent to the yoke portion to a location in which a winding position reaches the first restricting surface, the second layer of the coil strand is wound from the first restricting surface to a location in which a winding position reaches the position of the base end, while overlapping the first layer, and the third layer of the coil strand is wound from the position of the base end to a location in which a winding position reaches the second restricting surface, while overlapping the second layer, and the predetermined layer is the second layer, and wherein the reinforced portions are respectively formed in portions of the insulator adjacent to a flange cover wall and a tip end wall, and one of the reinforced portions is formed by setting the thickness of a portion adjacent to the vertical surface cover wall of the flange cover wall to be greater than those of other portions of the flange cover wall, and the other of the reinforced portions is formed by setting the thickness of a portion adjacent to the horizontal surface cover wall of the tip end wall to be greater than those of other portions of the tip end wall.