Closed type battery

The invention provides a closed type battery having no electrolyte leakage and improved airtightness, which comprises a battery header in which an electrode-drawing sheet of polarity opposite to that of a battery can is fixed by caulking to an insulating member fitted into a through-hole in a metal sheet while an electrode-leading pin remains inserted into the through-hole. An internal insulating sheet mounted on the surface of the metal sheet of the battery header located inside the battery can come into contact at two or more surfaces with an external insulating sheet mounted on a surface of the metal sheet of the battery header located outside the battery can.