Provided is a curved intraoral sensor including a scintillator configured to convert, to an optical signal, an X-ray received by penetrating a subject and to output the optical signal; an image sensor configured to convert the optical signal output from the scintillator to an electrical signal; and a controller configured to receive the electrical signal output from the image sensor, to convert the electrical signal to digital data, and to display an X-ray image of the subject on a screen using the converted digital data. The image sensor includes a first base having a curved surface formed on one surface and a complementary metal-oxide semiconductor (CMOS) formed to correspond to the curved surface on one surface of the first base.