PROBLEM TO BE SOLVED: To realize downsizing and simplification of a structure.SOLUTION: A high-frequency heating treatment device 1 comprises: a gantry 40 in which an upper electrode 42 is installed downward in an opening 41 a frame 10 that reciprocatably supports a treatment table part 20 on which a patient lies down and in which a lower electrode 22 is installed upward at a proper place approximately in a center a motor 34 that reciprocates the treatment table part 20 in order to position the lower electrode 22 between a treatment position in which it is opposed to the upper electrode 42 and a retreat position and an electrode contact piece 231 and a contact part 16 that supply high-frequency power to the lower electrode 22 at the treatment position.
