To provide a chemical volatilization container with which time of volatilization end of a volatile chemical can be clearly judged and an indicator with which the passage of time can be clearly judged.

The opening part of a container main body 2 is closed with a lid member 6, a closed space 7 is formed in the inside and the volatile chemical 8 (volatile substance) is stored in the space 7. The side parts 3 of the container main body 2 are formed in bellows. When the volatile chemical 8 (volatile substance) is permeated through the lid member 6 and starts volatilization, inner pressure of the space 7 is changed with following progress of the volatilization, the side parts 3 of the container main body 2 are compressed and deformed with following the change of the internal pressure of the space 7 and the side parts 3 of the container main body 2 are made into fixed forms when the volatilization is completed. Consequently, the time of the volatilization end of the volatile chemical 8 and passage of time can be clearly judged by visual observation of the shapes of the side parts 3 of the container main body 2.