PROBLEM TO BE SOLVED: To provide a wearing-type chemical diffusion apparatus capable of surely vaporizing and diffusing a large amount of chemicals to the atmosphere without using a motor and a battery.SOLUTION: A chemical diffusion instrument 1 is put on the body by a wearing implement 2 for use. The chemical diffusion instrument 1 with chemicals 4 and a rotating weight 5 mounted into a space part 3a of an instrument body 3, is adapted to rotate the rotating weight 5 by the movement of the body to vaporize the chemicals 4 and to diffuse the vaporized chemicals 4 to the atmosphere from an air flow port 6.