The present disclosure provides a stator of an electric rotating machine, a hairpin of a stator of an electric rotating machine, and a manufacturing method thereof. The stator for the electric rotating machine comprises a stator core, and a stator coil comprising hairpins. Each hairpin comprises a conductor, a film surrounding the conductor, a pair of insertion parts configured to be inserted into different slots, and a connection part connecting the insertion parts. The connection part comprises first and second bending parts bent with a predetermined radius of curvature such that the pair of insertion parts are insertable into different layers. The hairpins include first and second hairpins, each of the first and second hairpins configured to protrude from one end of the stator core by different protrusion lengths. Each of the first and second hairpins comprises a region configured to cross each other.