Because a series of data is recorded continuously, the recording quality of data recorded in course of recording cannot be evaluated. Accordingly, the laser output cannot be controlled properly and there are a deterioration and dispersion of the recording quality. Further, when the recording lasts for a long time, the temperature in the vicinity of laser rises due to the heat from the inside of a disc drive and the recording quality is deteriorated.To solve this, a series of data to be recorded is split and recording is made intermittently in a split data unit. The recording quality is evaluated by reproducing the data recorded nearby before each split data is recorded using a duration and control is performed by reflecting the evaluation result in the laser output so that the recording quality can be maintained satisfactorily over a series of the whole data to be recorded. Further, control is performed so that good recording quality can be maintained even in the recording that lasts for a long time by stopping the function of each part that ought to be operated even at recording or reproduction inside the disc drive in the duration, thereby suppressing a temperature rise.