PROBLEM TO BE SOLVED: To start radon inhalation therapy in a short time.SOLUTION: The radon mist generation unit includes: a radon elution water tank 4 accommodating radium ore 10 and water 11 and generating radon-containing water 11 containing eluted radon in the water 11 a pump 13 sending out the radon-containing water 11 in the radon elution water tank 4 to a radon-containing water supply passage 20 a radon-containing water storage tank 21 arranged in a downstream edge of the radon-containing water supply passage 20 and storing the radon-containing water 11 sent out from the pump 13 a heater 24 arranged in the radon-containing water storage tank 21, heating the radon-containing water 11 in the radon-containing water storage tank 21, separating radon from the heated radon-containing water 11, and generating steam and a radon guide passage 23 carrying the radon in the radon-containing water storage tank 21 by means of steam to a radon inhalation chamber and injecting radon mist in a concentration fit for radon inhalation therapy into the radon inhalation chamber.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2016,JPO&INPIT【課題】短時間でラドン吸入療法を開始できるようにする。【解決手段】ラジウム鉱石10及び水11を収容し、水11にラドンが溶け込んだラドン含有水(11)を生成するラドン溶出水槽4と、ラドン溶出水槽4内のラドン含有水(11)をラドン含有水供給路20に送り出すポンプ13と、ラドン含有水供給路20の下流側端部に配置され、ポンプ13から送り出されたラドン含有水(11)を貯留するラドン含有水貯留タンク21と、ラドン含有水貯留タンク21に設置され、ラドン含有水貯留タンク21内のラドン含有水(11)を加熱し、加熱したラドン含有水(11)からラドンを分離させると共に水蒸気を生じさせるヒータ24と、ラドン含有水貯留タンク21内のラドンを水蒸気によってラドン吸入室まで運び、ラドン吸入療法に適したラドン濃度のラドンミストをラドン吸入室内に噴出させるラドン案内路23と、を備えている。【選択図】図1