One mode of embodiment of the present invention makes it possible to provide a flexible light radiating probe which radiates light uniformly over 360 degrees at all azimuth angles from a light scattering and radiating portion, in such a way as to enable cancer in a plurality of locations dispersed over a wide area light to be irradiated simultaneously with light. The light radiating probe for photodynamic therapy according to the present invention is provided with an optical fiber which extends in an axial direction and which causes light from a light source to propagate, wherein the optical fiber includes: a light guide portion in which thin film cladding is provided on a side surface of a flexible core； and the light scattering and radiating portion, which causes the light that has propagated through the light guide portion to be scattered to the surrounding area in all directions, with respect to the axial direction of the flexible core, with a uniform intensity.
