A method of manufacturing a radiological image detection apparatus includes: bonding a phosphor to a sensor panel constructed such that a plurality of photoelectric conversion elements are arranged on a substrate; connecting a wiring member to a connection portion that is provided on a front face of the sensor panel opposite to the phosphor and that is electrically connected to the photoelectric conversion elements; covering with a first protective film the connection portion connected to the wiring member; peeling off the substrate from the sensor panel in which the first protective film is formed; and covering, with a second protective film having a moisture prevention property, at least a part corresponding to the connection portion in a rear face of a sensor portion exposed when the substrate is peeled off from the sensor panel.