To generate sure and stable operating pressure effectively and with high accuracy by an electroforming method, in a safety valve device for a battery for discharging gas generated inside by generating burst in the case where an inner pressure in the battery rises abnormally.

A safety valve device 1 which is operated when gas pressure in a battery rises, is composed of a thin plate-shaped base body part formed by an electroforming method; a fracture region part integratedly formed with a part of the base body part, and broken with a described pressure along a boundary defect part of a loop shape closed to the base body part, or a loop shape provided with an opening part an one part. Furthermore, the base body part and the fracture region part grow from a respectively different electroforming growing region, and the boundary defect part is composed on a joining part of respective growing electroforming ends.