A safety device for a storage battery includes a charge-discharge lead one end of which is connected to a positive electrode side of the storage battery and the other end of which is connected to a positive terminal of the storage battery; a pressure-sensing device which deforms in response to the increase of the pressure in the storage battery; and a cutting device for cutting the charge-discharge lead. The cutting device is pressed by the deformation of the pressure-sensing device to cut the charge-discharge lead.