The present invention provides a collimator, a radiation detecting device, and a radiation detecting device that can further remove scattered radiation. The collimator 20 of the present invention includes the radiation shielding portion 22 and the radiation transmitting portion 21, and the radiation shielding portion 21 has a lower radiation shielding rate than the radiation shielding portion 22, and penetrates the radiation shielding portion 22 and is solid. According to the collimator 20 of the present invention, since the X-ray transmitting portion 21 of the collimator 20 is solid, the X-rays on the low energy side scattered by the subject B in the X-ray transmitting portion 21 are absorbed. Therefore, the amount of noise contained in the X-rays detected by the radiation detecting element 30 is small, and an X-ray image with high resolution can be obtained.本發明提供一種可進一步去除散射放射線的準直器、放射線檢測裝置以及放射線檢查裝置。本發明的準直器20包括放射線屏蔽部22及放射線透過部21，所述放射線透過部21的放射線屏蔽率低於所述放射線屏蔽部22，貫通所述放射線屏蔽部22且呈實心。根據本發明的準直器20，準直器20的X射線透過部21呈實心，故而在X射線透過部21中經被測體B散射的低能量側的X射線被吸收。因此，放射線檢測元件30所檢測出的X射線中所含的雜訊少，從而可獲得解析度高的X射線圖像。
