PURPOSE: To provide a catheter ablation type medical care device which can prevent accessory symptoms such as blooding by cauterizing only a targeted lesion tissue without destroying (carbonizing) granulation, and substituting the lesion tissue with a good granulation tissue.

CONSTITUTION: This catheter ablation device 1 includes: a catheter portion 11 enclosing an endoscope 17 and a thermocouple, with the end face 17a of the endoscope 17 exposed to an end located at an affected part inside a subject for treatment, and having an internal electrode 16 which forms one end of the thermocouple; an external electrode 12 provided in a position outside the subject for treatment; a high-frequency power generator 13 formed between the internal and external electrodes 16, 12 in such a way as to be capable of generating high-frequency power of 2 to 20MHz and 1 to 200W; and a thermometer 14 connected to the other end of the thermocouple to detect the temperature of the internal electrode 16.