Disclosed is a phototherapy device which can irradiate an affected part, which is to be irradiated with light, with light selectively and intensively and can prevent eyes to undergo the direct irradiation with intense light emitted from a light source. Specifically disclosed is a phototherapy device comprising: a light guide member which has a contact surface that contacts with an affected part and an opposed surface that faces the contact surface and which serves as a light guide path and a first light source which can emit light having the main wavelength that depends on the wavelength range of infrared ray to the light guide path. In the phototherapy device, a material constituting the light guide member has a refractive index identical to or higher than the refractive index of a biological tissue.
