PURPOSE: To reduce the sliding between a recording medium and a head, by storing a disc in an enclosed case together with the head and increasing the air pressure in the enclosed case at start and stop of the recording medium for increasing the density of air.

CONSTITUTION: The enclosed case 1 containing the disc 3 and the head 4 and an air compressor 5 to pressurize the inside of the enclosed case 1 are provided. A sound sensor 8 is fitted to a bearing member of the head 4, and its output signal is displayed on an oscilloscope 9. When the medium is started with the inside of the enclosed case 1 at an atmospheric pressure, the waveform of a sound signal appears on the oscilloscope for 10±2sec. When the starting is made under 2.5 atm in the enclosed case 1, the waveform of the said sound signal disappears in about 3sec, and it is recognized that the head is floated and not slided. The start of sliding is detected with the oscilloscope 9 having the waveform of the sound signal, after the inside of the enclosed case 1 is increased to 2.5 atm and the rotating speed of the disc 3 decreases to some degree in the stopping, and the disc 3 is stopped in about 2sec after that.