To provide a tool for easily attaching/detaching a heat pipe used in a thermometer calibration furnace.

The heat pipe attachment/detachment tool includes a support part in which a placement face for placing the cylindrical heat pipe during attachment/detachment is provided at one end, a fastening tool having a through-hole to which the support part is inserted, and a fixing part sandwiching the support part with the fastening tool and performing fixation by pressing the support part against the heat pipe from the inner side. The placement face is fitted to a groove of an installation table arranged within a device using the heat pipe.