A powdery chemical agent spraying device (1) includes a container body (11) in which water (51) is to be put a cylindrical body (23) which is set so as to penetrate a cap (21) that covers a top opening (13) and both ends of which are present respectively in the inside and outside of the container body (11) one pair of sealing films (25,27) which seal respectively both ends of the cylindrical body (23) that is loaded with a powdery chemical agent (30) and which can be broken by the action of a pressure equal to or higher than a prescribed level and sodium bicarbonate (41) and citric acid (43) which react with the water (51) present in the container body (11) to generate a reaction gas.
