To provide a demodulator in which an error rate can be reduced in signal reproducing processing of an optical disk device.

In this demodulator 1, a slice signal input to a slice signal input terminal IN is read, a data word is demodulated from a code word, and it is output to a data word output terminal OUT. The demodulator is provided with a main demodulation table 14 outputting the data word corresponding to the word when a code word which does not infringe the minimum inversion interval is input, and a demodulation table 15 for infringement outputting a data word supposed to be right corresponding to the word when a code word which infringes the minimum inversion interval is input.