Abstract: A switch holder is made from a rubber or a plastic and has an endless ring-like form or an arcuate form cut at both ends to fit a finger of the worker who makes the welding. A switch having a small depression stroke is mounted on the periphery of the switch holder so as to be pressed by the flank of an adjacent finger. Thus, when the worker gripping a safety holder clamping a welding rod by his hand wearing the switch holder increases the gripping force, or when he intentionally increases the gripping force without holding anything, the push button is pressed by the flank of the adjacent finger. A protective mask body electrically connected to this switch accomodates a conversion means for converting the rotation of the shaft of a motor into a linear movement, and a light-shielding plate connected to the conversion means so as to move between a light shielding position where it covers the window of the mask body and a clearing position where it opens the window.