PROBLEM TO BE SOLVED: To provide an ablation catheter capable of suppressing positional deviation of a thermal element.SOLUTION: An ablation catheter comprises a shaft part 120 (122) inserted into a lumen 310 in a living body. The shaft part 120 (122) includes: an expansion body 124 which is expandable and shrinkable at least one or more thermal elements 126 and 128 thermally affecting a biological tissue and a deformation part 134 positioned on a base end side from the expansion body 124. The deformation part 134 has a curved area in contact with a wall tissue of the lumen 310 while being curved in a state in which the expansion body 124 is expanded and anchored to the wall tissue of the lumen 310. The thermal elements 126 and 128 are arranged in the curved area so as to come into contact with wall tissues Tand Tof the lumen 310.SELECTED DRAWING: Figure 4
