A stator, comprising: a stator core having a plurality of slots extending in an axial direction of the stator; a plurality of stator coils inserted into the plurality of slots and wound on the stator core, each of the stator coils having two ends electrically connected to form a joint portion; and an insulating part made of a dielectric material, formed as a single body, having a plurality of openings and a plurality of axially extending accommodation spaces partitioned from each other and communicating with the plurality of openings, joint portions of the stator coils being inserted into the plurality of accommodation spaces of the insulating part through the openings, the insulating part being configured to cover at least respective parts of the joint portions and provide a distance between neighboring joint portions, wherein each of the stator coils comprises: a first conductor and a second conductor configured to allow electric current to flow therethrough, the first conductor and the second conductor defining the two ends of the stator coil, respectively; and covering portions configured to cover respective parts of the first and second conductors (121a, 121b), excluding the joint portion, and provide protection, wherein the insulating part partially covers the covering portions, and wherein the insulating part further comprises a support portion protruding in the radial direction of the stator from an inner surface in the accommodation spaces, characterized in that the support portion is configured to be elastically deformable, the support portion being pressed by the covering portion or by at least one of the first and second conductors (121a, 121b) to be supported thereon, wherein the support portion has a hemispherical shape. a stator core having a plurality of slots extending in an axial direction of the stator; a plurality of stator coils inserted into the plurality of slots and wound on the stator core, each of the stator coils having two ends electrically connected to form a joint portion; and an insulating part made of a dielectric material, formed as a single body, having a plurality of openings and a plurality of axially extending accommodation spaces partitioned from each other and communicating with the plurality of openings, joint portions of the stator coils being inserted into the plurality of accommodation spaces of the insulating part through the openings, the insulating part being configured to cover at least respective parts of the joint portions and provide a distance between neighboring joint portions, wherein each of the stator coils comprises: a first conductor and a second conductor configured to allow electric current to flow therethrough, the first conductor and the second conductor defining the two ends of the stator coil, respectively; and covering portions configured to cover respective parts of the first and second conductors (121a, 121b), excluding the joint portion, and provide protection, wherein the insulating part partially covers the covering portions, and wherein the insulating part further comprises a support portion protruding in the radial direction of the stator from an inner surface in the accommodation spaces, characterized in that the support portion is configured to be elastically deformable, the support portion being pressed by the covering portion or by at least one of the first and second conductors (121a, 121b) to be supported thereon, wherein the support portion has a hemispherical shape. a first conductor and a second conductor configured to allow electric current to flow therethrough, the first conductor and the second conductor defining the two ends of the stator coil, respectively; and covering portions configured to cover respective parts of the first and second conductors (121a, 121b), excluding the joint portion, and provide protection, wherein the insulating part partially covers the covering portions, and wherein the insulating part further comprises a support portion protruding in the radial direction of the stator from an inner surface in the accommodation spaces, characterized in that the support portion is configured to be elastically deformable, the support portion being pressed by the covering portion or by at least one of the first and second conductors (121a, 121b) to be supported thereon, wherein the support portion has a hemispherical shape.