Provided is a chemical agent vaporizing/discharging device which can efficiently vaporize and discharge a chemical agent from a chemical agent retainer, and sufficiently diffuse the chemical agent, even when the device is used in a relatively large space or outdoors. A chemical agent vaporizing/discharging device 100 comprises: a chemical agent retainer 50 having a chemical agent retention layer 10 including interstices 11 for allowing retention of a volatile chemical agent, and a gas permeable layer 20 including voids 21 having a size larger than a size of the interstices 11; and a rotational drive part 60 for driving the chemical agent retainer 50. A shape and a size of the chemical agent retainer 50, and a rotational speed of the rotational drive part 60, are set so that a centrifugal effect of 10 to 150 (G) is obtained during rotation of the chemical agent retainer 50.