NOVELTY - A secondary battery (100) comprises container body (110) formed with exterior material (1) for secondary batteries in which metal foil layer and heat sealing layer (15) are successively laminated on surface side of base material layer and battery part (112) which is accommodated in container body as tabs (114) come outside. Exterior material for secondary batteries accommodates heat sealing layer inside, container body is made into a container shape, and belt-shaped edge portion which heat sealing layers are contacting is heat-sealed.    USE - A secondary battery for portable terminal devices, such as personal computer and mobile telephone, video camera, satellite, electric vehicle, electric motorcycle, and electric-power-assisted bicycle.    ADVANTAGE - Secondary battery can reduce moisture content and amount of drying up which permeate from side end surface of edge portion which heat-seals the heat sealing layers of exterior material.    DETAILED DESCRIPTION - A secondary battery (100) comprises container body (110) formed with exterior material (1) for secondary batteries in which metal foil layer and heat sealing layer (15) are successively laminated on surface side of base material layer and battery part (112) which is accommodated in container body as tabs (114) come outside. Exterior material for secondary batteries accommodates heat sealing layer inside, container body is made into a container shape, and belt-shaped edge portion which heat sealing layers are contacting is heat-sealed. In the value P according to formula P=(Qx R) divide by S (I) among the belt-shaped edge portions, the largest length direction of belt-shaped edge portion and machine direction (MD) of the heat sealing layer are parallel, where Q is thickness (mm) of heat sealing layer of heat seal part in belt-shaped edge portion, R is length (mm) of heat seal part in belt-shaped edge portion, and S is width (mm) of heat seal part in belt-shaped edge portion.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of a secondary battery.    Exterior material for secondary batteries (1)    Heat sealing layer (15)    Secondary battery (100)    Container body (110)    Battery part (112)    Tabs (114)