Abstract: A magnetic disk device having a base and a cover; a magnetic disk recording information on a recording surface thereof facing the base or the cover; a spindle motor fixed to the base and rotating the magnetic disk; a head for recording and reproducing the information to and from the recording surface of the magnetic disk; a slider having the head mounted thereto; a first suspension supporting the slider; a head arm provided between the magnetic disk and the base or the cover and supporting the first suspension on the side of the recording surface; and a carriage fixed to the base and swinging the head arm, moving the head in a radial direction of the magnetic disk and positioning the head. The magnetic disk device also has a second suspension provided on the base side or the cover side of the head arm and having a natural frequency substantially equal to a natural frequency of the first suspension.

Abstract: A magnetic disk device wherein a member having and suspension thereof a natural frequency similar to that of a head is disposed on an opposite surface of a head arm having one head mounted thereto via a suspension. The outermost shape (profile when the member is projected in a direction perpendicular to the surface of the magnetic disk) of the member having the natural frequency equal to that of the head and suspension thereof is similar to that of the head and the suspension or does not swell out from the profile of the head and the suspension. The member having the natural frequency similar to that of the head is provided to the head arm by the same device as that of the head.