Disclosed are a chemical carrier body capable of volatilizing a chemical stably for an extended period of time, a receptacle for retaining the chemical carrier body, an indicator adapted for displaying a degree of consumption of a chemical contained in the chemical carrier body, and a chemical heating, volatilizing apparatus adapted for heating the chemical carrier body.The chemical carrier body retaining receptacle is provided with at least one vent hole and has its inner surface spaced from the carrier body by a distance of 1 to 10 mm.The indicator has a mark gradually disappearing and a mark gradually appearing with a lapse of time of heating.The chemical heating, volatilizing apparatus has a heater element that is lager in size than the bottom surface of the chemical carrier body retaining receptacle and whose heat releasing surface is inclined at an angle of 0 to 70 degrees with respect to the plane on which the apparatus is placed.