Disclosed is a thermal battery which includes: a battery part which includes a plurality of unit batteries which are activated by heat; an insulation part which is arranged near the battery part and prevents the heat generated in the battery part from being discharged to the outside; a chemical heat source which is arranged in the insulation part and discharges the heat in the discharge of the battery part for an efficient insulation by increasing the inner temperature of the insulation part; and a heat storage part which is arranged in the insulation part and controls the inner temperature of the battery part by using the absorption or discharge of the heat generated when a phase is changed.
