Abstract: To provide automatic, efficient and effective cleaning before or after laser marking, a control of a laser marker identifies a start number presented on a display and retrieves drawing data and drawing position data of the start number from a memory. The control determines an area to be cleaned from the retrieved drawing data and drawing position data (A3). Then, the control retrieves condition data, such as scanning speed, for an area sweeping-type cleaning mode. An area cleaning scan is performed in which a beam spot of YAG laser beam almost entirely scans or sweeps once an area of the workpiece (A5) surface to be cleaned (A5). The cleaning scan is repeated a predetermined number of times. By the projection of the YAG laser beam onto the area, workpiece surface materials are thinly and lightly melted or sublimated so that stains, such as dirt, are removed as if with an eraser.