A method of manufacturing a curved-surface detector in which a detector configured to convert radiation into an electrical signal in order to acquire a radiographic image is curved so as to have a curved-surface shape, the method comprising: slimming a sensor substrate having photoelectric devices arranged therein to a predetermined thickness; seating the sensor substrate slimmed to the predetermined thickness on a jig curved so as to have a curved-surface shape such that the sensor substrate is curved so as to have a curved-surface shape; and joining a flexible scintillator substrate configured to emit light when being struck by radiation to an upper surface of the sensor substrate such that the sensor substrate maintains the curved-surface shape provided by the jig, wherein the scintillator substrate is joined to the sensor substrate via a junction layer in a state of being curved at curvature identical to curvature of the sensor substrate in order to maintain the curvature of the sensor substrate and thus to prevent separation between the scintillator substrate and the sensor substrate or deformation of the scintillator substrate and the sensor substrate at a junction portion between the scintillator substrate and the sensor substrate; wherein the step of slimming a sensor substrate to a predetermined thickness comprises sealing-treating a portion of the sensor substrate in which the photoelectric devices are mounted in order to prevent the photoelectric devices mounted in the sensor substrate from being exposed to a slimming medium configured to perform slimming; and wherein the step of sealing-treating a portion of the sensor substrate in which the photoelectric devices are mounted comprises: disposing a protective member having tolerance to the slimming medium so as to overlap the sensor substrate; and sealing outer edges of the sensor substrate and the protective member using a hermetic seal in a state in which the protective member overlaps the sensor substrate. slimming a sensor substrate having photoelectric devices arranged therein to a predetermined thickness; seating the sensor substrate slimmed to the predetermined thickness on a jig curved so as to have a curved-surface shape such that the sensor substrate is curved so as to have a curved-surface shape; and joining a flexible scintillator substrate configured to emit light when being struck by radiation to an upper surface of the sensor substrate such that the sensor substrate maintains the curved-surface shape provided by the jig, wherein the scintillator substrate is joined to the sensor substrate via a junction layer in a state of being curved at curvature identical to curvature of the sensor substrate in order to maintain the curvature of the sensor substrate and thus to prevent separation between the scintillator substrate and the sensor substrate or deformation of the scintillator substrate and the sensor substrate at a junction portion between the scintillator substrate and the sensor substrate; wherein the step of slimming a sensor substrate to a predetermined thickness comprises sealing-treating a portion of the sensor substrate in which the photoelectric devices are mounted in order to prevent the photoelectric devices mounted in the sensor substrate from being exposed to a slimming medium configured to perform slimming; and wherein the step of sealing-treating a portion of the sensor substrate in which the photoelectric devices are mounted comprises: disposing a protective member having tolerance to the slimming medium so as to overlap the sensor substrate; and sealing outer edges of the sensor substrate and the protective member using a hermetic seal in a state in which the protective member overlaps the sensor substrate. disposing a protective member having tolerance to the slimming medium so as to overlap the sensor substrate; and sealing outer edges of the sensor substrate and the protective member using a hermetic seal in a state in which the protective member overlaps the sensor substrate.