The invention provides an optical disc apparatus which prevents that a laser beam whose power is set at a read power level causes erroneous data recording or deletion. The optical disc apparatus includes an emission controller which controls an amount of an electrical current that a current supply portion supplies to a laser diode in order to control a level of emission power at which the laser diode emits the laser beam. The emission controller has a function to set levels of the emission power at the following transition processings: a transition processing after a read processing and before a write processing, a transition processing after a write processing and before a read processing, a transition processing between two read processings for respective areas, and a transition processing between two write processings for respective areas.