A magnetic head carriage device which comprises a head carriage body provided on a magnetic disk drive apparatus slidably in a radial direction of a magnetic disk and in parallel to a guiding axis, an upper arm provided on the head carriage body to have an upper magnetic head on its lower surface, and a plurality of bearing members each having an annular bearing portion and a mounting arm, the annular bearing portion into which a guiding shaft is inserted along the guiding axis, the mounting arm portion extending outwardly from the annular bearing portion, the mounting arm portion of each of the bearing members being fixed to the head carriage body such that the annular bearing portions are located laterally from the head carriage body. The magnetic disk drive apparatus employing this magnetic head carriage device can be constructed to suit the demands in the field, especially one having an overall thickness smaller than that of a conventional magnetic disk drive apparatus.