To provide a long-term continuous chemical reaction caused by the contact between a reactant accommodated in a container and a reactant outside the container, preventing the reactant outside the container from entering inside the container, so that no chemical reaction is caused in the container.

A gas exhalation device generates a gas by the contact between a first reactant accommodated in a container 2 and a second reactant disposed outside the container 2 and exhales the generated gas in the air. The container 2 includes an outlet part 21 through which the first reactant is discharged in a predetermined amount per unit time. The outlet part 21 is arranged away from the second reactant.