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.