PURPOSE: To give distinct marking without deformation of the thin object to be marked by letting a disc form marking head oppose to a snapper and giving high speed repetitive impacts to the snapper.

CONSTITUTION: Of the plural marks 3 mounted to the mark mounting hole 21 of a marking head 4, the marking head 4 is so rotated that the training end of the required mark 3 opposes to the leading end of a snapper 2. When the mark 3 is pressed onto the object to be marked, the mark 3 and snapper 2 are contacted by the pressing force thereof, and a grip part 8 advances against a resetting spring 9, by which a control valve 15 is opened. A piston 13 is reciprocated at high speeds by the compressed air being sent to a cylinder 12, thereby striking the trailing end of the snapper 2. This small impact force is repeatedly applied to the mark 3, by which stamping is accomplished in a short time. The depth of marking is adjusted by the length of the impact time or supply air pressure. This device is used for marking work, etc. of high pressure gas vessels, etc.