An escape groove, which is in the shape of an end-closed annulus having its center disposed on an axis of a steering shaft, is formed in an upper surface of a rotating case of a SRC. When a CPU performs a head load operation to load a composite head including the read head onto a data area of a disk medium from a ramp, the CPU receives the output of the read head amplified by the head IC as a detection result of an external magnetic field applied to an HDD. The entrainer and the actuating device are connected to each other via a damping spring. An absorbent article comprising a liquid pervious cover sheet, a liquid impervious backsheet and a multiple layer water-absorbent core of the invention is also described.