PURPOSE: To obtain an even reproducing RF signal by providing first and second checking and recording areas in the trial writing area of an address data area at the time of recording,
CONSTITUTION: Recording data supplied from a terminal 21 are given to a recording data processing part 22. In the processing part 22, the trial writing area for a header becomes a first checking area AR1 whose reproducing level is zero, the heading part of respective data byte area becomes a first checking and recording area AR2 which is magnetized so as to making its recording layer zero, and then the recording data are recorded. At the time of reproducing, the trial writing area becomes the area AR1 and the reference signal of the reproducing RF signal can be detected. This reference signal is used for clamping the reproducing RF signal. A clamping circuit 11 uses the clamping voltage to clamp the reproducing RF signal and transmits it to an A/D converter 12. Thus, the accuracy of A/D conversion can be improved and the occurrence of erroneous data can be reduced.