[Problem]There is provided a sealed cell with no possibility of liquid leakage without sacrificing volume energy density.[Measures to solve the problem]The sealing body is characterized as follows: the sealing body for a sealed cell comprises a substantially rectangular-shaped sealing plate having a through hole and/or a thinner portion that is thinner than other portions, and an electrode external terminal attached to the through hole and/or the thinner portion; and the periphery of the sealing body in the vicinity of the terminal plate is thicker than other portions. The thicker portion is 0.1 to 0.4 mm thicker than the other portions, and the width of the thicker portion is preferably 0.1 to 0.5 mm.