To provide a manual caulking machine for a flat battery, which has a compact shape in comparison with a conventional manual caulking machine, and is capable of reliably caulking the flat battery with small force, and favorably usable in a standard glove box.

A gear mechanism unit 70 includes an operational unit 80 to be turned by an operator, an input shaft 40 interlockingly rotated with the operational unit 80, a slide member 30 subjected to the reciprocating motion on a predetermined track at the predetermined stroke interlockingly with the rotation of the input shaft 40, an output shaft 42 to be connected to the input shaft 40 via the gear mechanism unit 70, a crank member 50 to be rotated with the output shaft 42, and a link mechanism unit to be connected to the crank member 50 and the slide member 30. The rotational torque of the output shaft 42 is larger than the rotational torque of the input shaft 40.