The purpose of the invention is to enable a type of X-ray generating apparatus that employs an ultraviolet laser to be used in a medical X-ray irradiation apparatus application and to stabilize generation of X-rays. An X-ray irradiation apparatus is provided with: a flexible tube section comprising a flexible tube having a conduit therein, and an ultraviolet fiber that is inserted within the conduit and propagates an ultraviolet laser； and a head section comprising an electron beam emitting element that receives the ultraviolet laser emitted from the ultraviolet fiber and emits an electron beam, a metal piece that receives the electron beam emitted from the electron beam emitting element and emits X-rays, and an X-ray transmission window that allows the X-rays emitted from the metal piece to transmit therethrough. The head section is arranged at the other-end side of the flexible tube section such that when one end of the ultraviolet fiber is irradiated from the one-end side of the flexible tube section with the ultraviolet laser, the electron beam emitting element is irradiated from the other end of the ultraviolet fiber with the ultraviolet laser propagating in the ultraviolet fiber. At least the space between the electron beam emitting element and the metal piece within the head unit is made to be a vacuum area.
