WELDING MASK

A welding mask according to an embodiment of the present disclosure includes a welding mask body having a laser passage portion configured to allow a laser emitted into a housing of a battery cell to pass therethrough, the welding mask body configured to cover an open portion on a side of the housing; and an insertion guide having a hollow structure, connected to the laser passage portion, and configured to be inserted into a winding center hole of an electrode assembly received in the housing.