A rotary electric machine having an integrated drive control device, the rotary electric machine comprising: a motor; and a drive control device provided on another end portion side of an output shaft of the motor, which is opposite to an output mechanism provided on one end portion side of the output shaft of the motor, for controlling drive of the motor, the motor and the drive control device being provided so as to be integrated with each other, the motor comprising: a stator including a stator core formed by laminating thin steel plates, around which a stator winding is wound; a rotator having the output shaft extending along a center axial line, and being provided rotatably on an inner-diameter side of the stator; a motor housing having a cylindrical shape, for housing the stator core therein; and a mounting housing being provided on the one end portion side of the output shaft so as to close an opening portion of the motor housing, and having mounted thereto an output mechanism housing for housing the output mechanism therein, the motor housing and the mounting housing being joined to each other by joint means, which is provided to the opening portion; the joint means comprises a fixing screw; the rotary electric machine further comprising a fitting portion being formed in a joint region in which the motor housing and the mounting housing are joined to each other, and extending along an axial direction so as to hold the motor housing and the mounting housing in close contact with each other characterized in that the motor housing is made of a steel material, the mounting housing comprises a cast member; and in that the fixing screw is provided to a bent portion formed on an end portion of the motor housing so as to be bent inward; the fitting portion being in close contact with an outer circumferential wall surface of the motor housing. a motor; and a drive control device provided on another end portion side of an output shaft of the motor, which is opposite to an output mechanism provided on one end portion side of the output shaft of the motor, for controlling drive of the motor, the motor and the drive control device being provided so as to be integrated with each other, the motor comprising: a stator including a stator core formed by laminating thin steel plates, around which a stator winding is wound; a rotator having the output shaft extending along a center axial line, and being provided rotatably on an inner-diameter side of the stator; a motor housing having a cylindrical shape, for housing the stator core therein; and a mounting housing being provided on the one end portion side of the output shaft so as to close an opening portion of the motor housing, and having mounted thereto an output mechanism housing for housing the output mechanism therein, the motor housing and the mounting housing being joined to each other by joint means, which is provided to the opening portion; a stator including a stator core formed by laminating thin steel plates, around which a stator winding is wound; a rotator having the output shaft extending along a center axial line, and being provided rotatably on an inner-diameter side of the stator; a motor housing having a cylindrical shape, for housing the stator core therein; and a mounting housing being provided on the one end portion side of the output shaft so as to close an opening portion of the motor housing, and having mounted thereto an output mechanism housing for housing the output mechanism therein, the motor housing and the mounting housing being joined to each other by joint means, which is provided to the opening portion; the joint means comprises a fixing screw; the rotary electric machine further comprising a fitting portion being formed in a joint region in which the motor housing and the mounting housing are joined to each other, and extending along an axial direction so as to hold the motor housing and the mounting housing in close contact with each other characterized in that the motor housing is made of a steel material, the mounting housing comprises a cast member; and in that the fixing screw is provided to a bent portion formed on an end portion of the motor housing so as to be bent inward; the fitting portion being in close contact with an outer circumferential wall surface of the motor housing.