The present invention provides an adjusting method for recording condition, capable of implementing an evaluation method of a reproduced signal with high reliability and high efficiency, and an optical disc device employing the evaluation method, under assumption that continuous 2T count included in a predetermined evaluation bit array is denoted by i and that length of evaluation bit array of interest is given by (5 + 2i), judgment is passed on whether binary bit arrays include the evaluation bit array. Previously prepared are the error vectors calculated on the basis of target signals corresponding to the evaluation bit arrays and the target signals derived from the binary bit arrays, and the selection of a desired error vector is performed depending on the result of the judgment. At the same time, an equalized error vector is calculated from the target signal derived from the binary bit array and the reproduced signal, and the inner product of the equalized error vector and the selected error vector is calculated. Thereby, a circuit size required by evaluating the reproduced signal may be reduced.