An airtight-type electric motor comprising: a rotor including a rotor member and a shaft with the rotor member fixed thereto; a stator including a stator core located radially outside of the shaft and a plurality of winding portions mounted on the stator core, the stator core including core end portions which oppose to each other in an axial direction of the shaft; a pair of bearings (11,13) that rotatably support the shaft; a pair of end brackets (7, 9) with the pair of bearings (11,13) respectively fixed thereto, the pair of end brackets (7, 9) being fixed to the core end portions of the stator core through fitting structures; a cylindrical housing that is located radially outside of the stator and surrounds the stator, the housing including housing end portions which oppose to each other in the axial direction; and a pair of airtight coupling structures (37,39) which airtightly couple the end brackets (7,9) to the housing end portions, the housing and the stator core are not directly coupled; characterized in that: the end brackets (7,9) comprise: a bracket body; an inside rib integrally formed with the bracket body and inserted into inside the stator core to be fitted into the core end portion of the stator core; and an annular outside rib integrally formed with the bracket body and located radially outside of the inside rib to be inserted into inside the housing end portion, the outside rib being in contact against an end surface of the core end portion of the stator core and being airtightly coupled to the housing end portion of the housing through the airtight coupling structure (37,39); the bearings (11, 13) are fitted inside of the inside rib; and the airtight coupling structure (37,39) comprises: a first O-ring arranged between the outside rib and an inner circumferential surface of the housing end portion; and a second O-ring arranged between an end surface of the housing end portion and the bracket body of the end brackets (7,9). a rotor including a rotor member and a shaft with the rotor member fixed thereto; a stator including a stator core located radially outside of the shaft and a plurality of winding portions mounted on the stator core, the stator core including core end portions which oppose to each other in an axial direction of the shaft; a pair of bearings (11,13) that rotatably support the shaft; a pair of end brackets (7, 9) with the pair of bearings (11,13) respectively fixed thereto, the pair of end brackets (7, 9) being fixed to the core end portions of the stator core through fitting structures; a cylindrical housing that is located radially outside of the stator and surrounds the stator, the housing including housing end portions which oppose to each other in the axial direction; and a pair of airtight coupling structures (37,39) which airtightly couple the end brackets (7,9) to the housing end portions, the housing and the stator core are not directly coupled; characterized in that: the end brackets (7,9) comprise: a bracket body; an inside rib integrally formed with the bracket body and inserted into inside the stator core to be fitted into the core end portion of the stator core; and an annular outside rib integrally formed with the bracket body and located radially outside of the inside rib to be inserted into inside the housing end portion, the outside rib being in contact against an end surface of the core end portion of the stator core and being airtightly coupled to the housing end portion of the housing through the airtight coupling structure (37,39); a bracket body; an inside rib integrally formed with the bracket body and inserted into inside the stator core to be fitted into the core end portion of the stator core; and an annular outside rib integrally formed with the bracket body and located radially outside of the inside rib to be inserted into inside the housing end portion, the outside rib being in contact against an end surface of the core end portion of the stator core and being airtightly coupled to the housing end portion of the housing through the airtight coupling structure (37,39); the bearings (11, 13) are fitted inside of the inside rib; and the airtight coupling structure (37,39) comprises: a first O-ring arranged between the outside rib and an inner circumferential surface of the housing end portion; and a second O-ring arranged between an end surface of the housing end portion and the bracket body of the end brackets (7,9). a first O-ring arranged between the outside rib and an inner circumferential surface of the housing end portion; and a second O-ring arranged between an end surface of the housing end portion and the bracket body of the end brackets (7,9).