An applicator (10) has a syringe (11) filled with a drug such as a hemostatic or a biological adhesive. A drug ejecting part (12) is provided to one end of the syringe (11). A plunger (13) is inserted from the other end of the syringe (11). A gas flow passage (17) for supplying a compressed gas to the drug ejecting part (12) is formed in a support part (14) for supporting the syringe (11). The gas flow passage (17) has a valve (18). The valve (18) is opened by pressing of a trigger (16) attached to a grip part (15) of the support part (14). An operator grasps the grip part (15) in one hand. When the operator presses a pressing part (13A) of the plunger (13) with a thumb, the drug in the syringe (11) is ejected from a nozzle (12A) of the drug ejecting part (12). When the operator presses the trigger (16) with an index finger, the compressed gas is ejected from an air cap (12B) of the drug ejecting part (12). When the drug and compressed air are simultaneously ejected, the drug is atomized.