Catheter tube capable of irradiating laser optimized in light radiation efficiency and distribution, used in photosensitization reaction treatment is provided by simple process. Catheter tubes provided to medical device inserted into a living body to irradiate target site for treatment or examination with a light to treat or examine the site. The tubes being formed of material optically having transparency, provided with insertion hole for light diffusing body, and one or more other holes different from the insertion hole, in a manner extending in longitudinal direction of catheter tubes. Inside the other holes, space is present adjacent to inner wall thereof, the inner wall forming optical interface between the material and gas phase or liquid phase in the space, which are different from each other in refractive index, to conjointly form reflection surface for adjusting radiation distribution of light emitted by light diffusing body.
