In plasma irradiation device 20 of plasma application system 10, laser light 80 is emitted coaxially in an application direction of plasma. When plasma is applied to patient 12 from plasma irradiation device 20, the patient is imaged by imaging device 24, and an application position of the laser light on a processing target object, that is, plasma application position 82 is calculated by control device 22 based on captured image data. An image corresponding to the application position is displayed on display device 26. Accordingly, a clinician is able to recognize the application position of the plasma and it becomes possible to appropriately apply plasma to the patient.
