An intraoral sensor 1 includes: a case 4 having a first plate-shaped portion 12 and a second plate-shaped portion 16 that face each other a photodetecting element 34 contained in the case 4 so that a light incident surface faces the first plate-shaped portion 12 a cover 6a, arranged on the outer surface of the second plate-shaped portion 16, for covering an opening 16a and fixing members 32a and 32b, arranged between the second plate-shaped portion 16 and the cover 6a, for fixing to the case 4 a signal cable 24 connected to the photodetecting element 34 extending via the opening 16a from the inside to the outside of the case 4. This enables improvement of a connection strength between the case of the imaging device and the signal cable extending from an opposite side of the imaging surface.