To always execute proper detection of radiation by suppressing damage of a substrate when applying load.

A sensor array substrate 212 and an opposite substrate 213 are cut into desired size by irradiation of laser. An irradiation face of cutting laser is the face of a reverse side to the installation face of a signal detection part 151 concerning the sensor array substrate 212, and is the face of a reverse side to the face of a side in which radiation is irradiated concerning the opposite substrate 213. Thereby even when applying load on a detector unit 21 in photographing radiation images, the proper detection of radiation is always executed by suppressing damage of the sensor array substrate 212 or the like.