An apparatus for relaxing smooth muscles of a human body, capable of directly radiating light having a predetermined wavelength range for inducing relaxation of the smooth muscles onto acupuncture points related to an organ consisting of smooth muscles via an electrode probe. The apparatus includes a controller body to determine whether a light radiation mode is selected and an operation is started through a direct manipulation using a switch, and output an LED driving signal to an electrode probe connection terminal and wired and wireless electrode probes to be attached to/detached from the terminal to be electrically connected to/disconnected from the controller body, and to be driven by the driving signal to emit light having a predetermined wavelength range which increases concentration of a material for relaxing the muscles. Accordingly, the apparatus promotes blood and lymph circulation in an organ consisting of smooth muscles by relaxing those muscles.