An optical disk apparatus has a highly accurate trial writing function corresponding to a PRML system and copes with a bad jitter of a 2Tw mark in order to realize an optical disk, the recordingreproduction of which is enabled in both a DVD and a Blu-ray Disc by a drive. A controller is coupled to the first measuring apparatus and the second measuring apparatus. Next a single receive interface is selected for testing. Each of the second number of ECC blocks is configured to store ECC information. The process of the present invention comprises the following steps.