Embodiments of the invention provide a magnetic disk drive that can effectively suppress the influence of an air stream coupled with the rotation of a magnetic disk. In one embodiment, the magnetic disk drive is adapted to have a disk assembly that includes at least one magnetic disk medium, a head assembly that includes at least one magnetic head which writes magnetic signals onto and reads them out from the magnetic disk medium or media, and at least one arm which supports the magnetic head(s), a ramp assembly that includes at least one ramp which guides the magnetic head(s) to a required retreat position(s) when the particular magnetic head is moved away from the associated magnetic disk medium, and shroud fins as many in number as the magnetic disk media, in which case, each shroud fin is disposed integrally with the ramp assembly and in association with and next to either of the magnetic disk media in order to guide an air stream produced by the rotation of the disk assembly.