Abstract: A magnetic disc memory device comprises a rotatable member, a stationary member for supporting the rotatable member, dynamic pressure bearing provided between the stationary member and the rotatable member, a plurality of information recording magnetic discs mounted in axially spaced apart relationship on the outer peripheral portion of the rotatable member, an annular rotor provided on the outer peripheral portion of the rotatable member in axially spaced apart relationship with the magnetic discs, an annular stator secured to the stationary member and radially facing the annular rotor, the stator and the rotor together constituting an electric motor, and a case secured to the stationary member and surrounding the magnetic discs, the rotatable member, the rotor and the stator to protect them from extraneous influence.