To provide an arc stud welding device which has fewer consumables and with which the reliability of welding is raised, execution of work is simplified and time is saved.

In the arc stud welding device 10 in which, in a state where a shielding member 13 is mounted in a welding part of a welding material 16 attached at the tip of a stud welding gun 11, by producing an arc between the welding material and the material to be welded, the welding material 16 is welded on the material to be welded, the shielding member 13 is constituted of a 1st and 2nd shield frames 14, 15 having structure divided in two. Also the 1st shield frame 14 is attached to the stud welding gun 11 through a supporting member 12 and the 2nd shield frame 15 is attached to the 1st shield frame 14 through a hinge 20 so as to can be opened and closed. In the case the 2nd shield frame 15 is made to coalesce with the 1st shield frame 14, holding means 24 for holding that state is provided and, moreover, an inert gas supplying part 42 is provided on the shielding member 13.