Laminate type battery and battery module incorporating the laminate type battery

A laminate type battery includes a laminate battery case and an electrode assembly. The laminate battery case includes two laminate films each having a metal layer and plastic layers provided on both faces of the metal layer, and has a welded portion in which peripheral edges of the two laminate films are welded to each other. The electrode assembly is enclosed in the laminate battery case, and has a positive electrode plate, a negative electrode plate, and a separator disposed therebetween. An internal gas pressure sensing portion, in which the inner plastic layer of each of the laminate films is absent and the metal layers are in contact with each other so as to be in an electrically conductive state, is formed in a portion of the welded portion. A voltage detection hole, in which the outer plastic layer is absent and the metal layer is exposed, is formed in a surface of each of the two laminate films.