Abstract: The invention aims to provide a pest controller that reduces the possibility of unintentional contact with a chemical substance, that is easy to carry, that is able to maintain a sufficient pest-controlling effect in a portable size, and further that is easy to adjust a pest-controlling effect. A pest controller (1) of the present invention includes a container (8) holding a chemical substance (22) therewithin, wherein the container includes a substance exposing portion communicating with the inside of container (8), and a cover for sealing, the chemical substance containing an active ingredient with a pest-controlling effect, and the active ingredient being volatilizable at a normal temperature.