PURPOSE: To enable the burned ash to be slugged by a method wherein a laser beam is irradiated against the burned ash which is discharged by a specified volume from the burned ash storage unit installed at a later stage of the incinerator.

CONSTITUTION: Combustioned ash storage unit 9 is installed at a later stage of the incinerator 1, a metering volume feeder 10 is placed at a proper bottom part in the storage unit 9, the burned ash 6 which is fed by a transferring means 8 is discharged to the lower water tank 11 by a specified volume. Over the discharged end is arranged a laser generator device 12 to enable a laser beam to be irradiated against the burned ash 6 dropped from the discharged end. With this arrangement, the burned ash 6 is melted by an irradiation energy of the laser beam during the ash is reached from the discharge end to the water surface in the water tank 11, and just after that the ash is dropped into the water to apply a rapid cooling thereto.