A radiation detection apparatus comprising: a radiation detection panel configured to detect X-ray radiation; a circuit board configured to drive the radiation detection panel ; a flexible circuit board configured to electrically connect the radiation detection panel to the circuit board ; a support member that is configured to support the radiation detection panel on one surface thereof and to support the circuit board on another surface thereof and that has electrical conductive property; a heat insulation member arranged between the radiation detection panel and the circuit board ; a housing that is configured to accommodate the radiation detection panel , the circuit board , the support member , and the heat insulation member and has electrical conductive property; a heat conduction member that is accommodated in the housing , is connected to the support member and the housing , and is configured to achieve both, electrical conduction between the support member and the housing and heat conduction from the support member to the housing ; an entrance window which is arranged opposite to the radiation detection panel with a gap and connected to the housing and through which radiation can pass; and a frame-shaped partition member provided between the radiation detection panel and the housing , wherein the housing has an opening that overlaps the entrance window , and the partition member partitions a space into a first space (Sa) surrounded by the housing and the support member and a second space (Sb) surrounded by the radiation detection panel and the entrance window to suppress entrance and exit of an atmosphere between the first space (Sa) and the second space (Sb). a radiation detection panel configured to detect X-ray radiation; a circuit board configured to drive the radiation detection panel ; a flexible circuit board configured to electrically connect the radiation detection panel to the circuit board ; a support member that is configured to support the radiation detection panel on one surface thereof and to support the circuit board on another surface thereof and that has electrical conductive property; a heat insulation member arranged between the radiation detection panel and the circuit board ; a housing that is configured to accommodate the radiation detection panel , the circuit board , the support member , and the heat insulation member and has electrical conductive property; a heat conduction member that is accommodated in the housing , is connected to the support member and the housing , and is configured to achieve both, electrical conduction between the support member and the housing and heat conduction from the support member to the housing ; an entrance window which is arranged opposite to the radiation detection panel with a gap and connected to the housing and through which radiation can pass; and a frame-shaped partition member provided between the radiation detection panel and the housing , wherein the housing has an opening that overlaps the entrance window , and the partition member partitions a space into a first space (Sa) surrounded by the housing and the support member and a second space (Sb) surrounded by the radiation detection panel and the entrance window to suppress entrance and exit of an atmosphere between the first space (Sa) and the second space (Sb). <EOS>