Abstract: An acupuncture needle for treating diseased parts in a patient's body by sticking its needle point into the diseased parts comprises: a needle body which consists of an optical fiber for transmitting light from a light source over nearly the entire length of the needle, and a needle point attached to the front end of the optical fiber; and a means such as a light collecting lens for applying light from the light source onto the end surface of the optical fiber so that the light can be transmitted through the optical fiber. The needle point inserted into the affected part of the body collects light from the light source and radiate light or heat against the affected part, producing improved remedial effects.