An outer stator of a rotary electric machine, the stator comprising: a stator core that includes a plurality of slots, the stator core having a preset space on an innermost radial side of each slot; and a plurality of conductor segment coils that each have a U-shape, each conductor segment coil being assembled in a corresponding one of the slots with the segment coil being inserted into the slot from one side in an axial direction of the stator core and a portion of the conductor segment coil that protrudes out on the other side in the axial direction of the stator core being bent, characterized in that a sectional area of the U-shaped portion of the conductor segment coil that protrudes out from one side in the axial direction of the stator core is greater than a sectional area of a tip end portion of the conductor segment coil that protrudes out from the other side in the axial direction of the stator core; the sectional area of the tip end portion of the conductor segment coil that protrudes out from the other side in the axial direction of the stator core is greater than a sectional area of an in-slot portion of the conductor segment coil, wherein a dimension of the tip end portion of the conductor segment coil that protrudes out from the other side in the axial direction of the stator core along a circumferential direction of the slot is equal to a dimension of the in-slot portion of the conductor segment coil along the circumferential direction of the slot; and a dimension of the tip end portion of the conductor segment coil that protrudes out from the other side in the axial direction of the stator core along a radial direction of the slot is greater than a dimension of the in-slot portion of the conductor segment coil along the radial direction of the slot; and in that the stator further comprises a spacer arranged in the preset space, a radial dimension (ΔL) of the preset space being greater than a difference between a radial dimension of the sectional area of the tip end portion of the conductor segment coil that protrudes out from the other side in the axial direction and a radial dimension of the sectional area of an in-slot portion of the conductor segment coil. a stator core that includes a plurality of slots, the stator core having a preset space on an innermost radial side of each slot; and a plurality of conductor segment coils that each have a U-shape, each conductor segment coil being assembled in a corresponding one of the slots with the segment coil being inserted into the slot from one side in an axial direction of the stator core and a portion of the conductor segment coil that protrudes out on the other side in the axial direction of the stator core being bent, characterized in that a sectional area of the U-shaped portion of the conductor segment coil that protrudes out from one side in the axial direction of the stator core is greater than a sectional area of a tip end portion of the conductor segment coil that protrudes out from the other side in the axial direction of the stator core; the sectional area of the tip end portion of the conductor segment coil that protrudes out from the other side in the axial direction of the stator core is greater than a sectional area of an in-slot portion of the conductor segment coil, wherein a dimension of the tip end portion of the conductor segment coil that protrudes out from the other side in the axial direction of the stator core along a circumferential direction of the slot is equal to a dimension of the in-slot portion of the conductor segment coil along the circumferential direction of the slot; and a dimension of the tip end portion of the conductor segment coil that protrudes out from the other side in the axial direction of the stator core along a radial direction of the slot is greater than a dimension of the in-slot portion of the conductor segment coil along the radial direction of the slot; and in that the stator further comprises a spacer arranged in the preset space, a radial dimension (ΔL) of the preset space being greater than a difference between a radial dimension of the sectional area of the tip end portion of the conductor segment coil that protrudes out from the other side in the axial direction and a radial dimension of the sectional area of an in-slot portion of the conductor segment coil.