A thermal caulking device which is configured to caulk a portion of a plastic part as an object to be caulked, the thermal caulking device comprising: a metal tip having a pressing part which is configured to press the object to be caulked and a heating rod which is provided upright at a center part of the pressing part; heating means for heating the heating rod; a cooling pipe which is configured to cool the heating rod; cooling fluid supply means for supplying a cooling fluid to the cooling pipe; a holder which holds the metal tip and the cooling pipe so that the cooling pipe delivers the cooling fluid toward the heating rod; and control means for controlling the heating means and the cooling fluid supply means, wherein the control means are configured to heat the pressing part from the heating rod by the heating means, and are further configured after the object to be caulked is thermally caulked by the pressing part, to supply the cooling fluid from the cooling fluid supply means to the cooling pipe to cool the pressing part from the heating rod, wherein the holder holds the metal tip and the cooling pipe so that a leading end portion of the cooling pipe covers the outer peripheral surface of the heating rod of the metal tip with a clearance therebetween, characterized in that the heating means has a coil which is wound on the outer peripheral surface of the leading end portion of the cooling pipe, and a power source which is configured to supply a high-frequency current to the coil, and the control means are further configured to apply a high-frequency current from the power source to the coil, and are further configured to heat the pressing part from the heating rod by high-frequency induction heating through the coil. a metal tip having a pressing part which is configured to press the object to be caulked and a heating rod which is provided upright at a center part of the pressing part; heating means for heating the heating rod; a cooling pipe which is configured to cool the heating rod; cooling fluid supply means for supplying a cooling fluid to the cooling pipe; a holder which holds the metal tip and the cooling pipe so that the cooling pipe delivers the cooling fluid toward the heating rod; and control means for controlling the heating means and the cooling fluid supply means, wherein the control means are configured to heat the pressing part from the heating rod by the heating means, and are further configured after the object to be caulked is thermally caulked by the pressing part, to supply the cooling fluid from the cooling fluid supply means to the cooling pipe to cool the pressing part from the heating rod, wherein the holder holds the metal tip and the cooling pipe so that a leading end portion of the cooling pipe covers the outer peripheral surface of the heating rod of the metal tip with a clearance therebetween, characterized in that the heating means has a coil which is wound on the outer peripheral surface of the leading end portion of the cooling pipe, and a power source which is configured to supply a high-frequency current to the coil, and the control means are further configured to apply a high-frequency current from the power source to the coil, and are further configured to heat the pressing part from the heating rod by high-frequency induction heating through the coil.