A floppy disk unit rotates a recording medium loaded thereon and reads information from or records information on the medium with magnetic heads. A bearing for rotatably supporting the medium includes a bearing member made of sintered alloy, and the member is formed with a band-like projection along the edge of its end portion. A metal support plate has a through hole perforated by press work or the like and a portion formed along the edge thereof, which is larger in diameter than the rest of the through hole and provides a gap between the through hole and the end portion of the bearing member fitted therein. The band-like projection is caulked and fills up the gap to be substantially flush with the support plate, thereby fixing the bearing member to the support plate. Thus, the whole unit is reduced both in height and weight, and the manufacturing cost decreases. The unit is provided with an adjustment portion for adjusting beforehand portions of the magnetic heads with respect to the medium. The adjustment portion is arranged in a position where it is prevented from being vertically overlapped with the loaded medium so that adjustment of the unit can be performed from above easily and reliably in stable manner.