PROBLEM TO BE SOLVED: To provide a radiation generating device in which radiation visual field can be confirmed by visual observation and the like without the use of a large device, and shading is reduced.SOLUTION: A reflection plate 4 including a reflection surface 4a for reflecting visible light and a compensation member 9 are configured by a triangular prism having a right triangle cross section. The reflection plate 4 and the compensation member 9 are joined together via the reflection surface 4a to be a rectangular parallelepiped. A transmission length of radiation 11a radiated in a direction of an angle &thetas； to a radiation central axis 11 and a transmission length of radiation 11b radiated in a direction of an angle -&thetas； that transmit the reflection plate 4 are compensated by the compensation member 9, so that a total transmission length of the radiation 11a and a total transmission length of the radiation 11b that transmit the reflection plate 4 and the compensation member 9 become the same.【課題】装置を大型化させることなく、放射線視野を目視等で確認することが可能で、且つ、シェーディングを低減した放射線発生装置を提供する。【解決手段】可視光を反射する反射面４ａを備えた反射板４と、補償部材９とを、断面が直角三角形の三角柱で構成し、反射面４ａを介して反射板４と補償部材９とを接合して直方体とし、放射線中心軸１１に対して角度θの方向に放射された放射線１１ａと、－θの方向に放射された放射線１１ｂとが、反射板４を透過する透過長を補償部材９で補償し、反射板４及び補償部材９を透過する透過長の合計が等しくなるようにする。【選択図】図２
