To prevent a heating lamp from being broken owing to a sticking of drop of water even when used under a low-temperature condition by covering the open-side outer peripheral surface of an internal cylinder with a heat insulating member which has heat resistance.
A couple of heat exchanging elements 70 each have an internal cylinder 71 and an external cylinder 72 respectively. The internal cylinder 71 is made of a light-transmissive material such as quartz glass and the internal cylinder 71 is uniformly cylindrical having both the ends opened. The heat exchanging elements 70 are provided with heat insulating members 80 on the outer peripheral surfaces of both the end parts of the respective internal cylinders 71. The heat insulating members 80 are made of resin which has sufficient heat insulating property and heat resistance and also has relatively large rigidity. Each heat insulating member 80 is fitted onto the outer peripheral surface of the internal cylinder 71 through a center hole 80a while one end surface is made to abut against the external end surface of the external cylinder 72 and the other end part is projected from the external end part of the internal cylinder 71, and then fitted to the external end surface of the external cylinder 72 with a screw.
KAMEI TOSHIYUKI
MIYAMOTO SHUNSUKE
