An injection needle has an opening at a distal end thereof the injection needle and defines a hole. An optical fiber is configured to output a light from a light source and inserted in the hole. The optical fiber has a distal end positioned on an inner side of the opening. A protector is configured to transmit the light and is positioned further towards an opening side of the injection needle than the distal end. The protector is configured to prevent adherence of tissue to the optical fiber. The light emitted from the optical fiber is configured to irradiated onto a treatment target in a state in which the injection needle is inserted into skin, the distal end is positioned on an inner side of the opening, and the protector is positioned further towards the opening side of the injection needle than the distal end.