Six record areas for predetermined data that has been encoded and digitally modulated are formed in a data record area on a disc. The record areas have different offset compensation amounts. The offset compensation amounts allow all offset amounts that may take place in an error correction code encoder to be compensated. Thus, regardless of the offset amount generated by the error correction code encoder, encoded and modulated data that has been generated by the conventional EFM modulating system and recorded in one of the record areas securely causes DSV to deviate. Each of the record areas is set to a sufficient length that allows the effect of which DSV deviates to be recognized.