A data reading device for a camera can provide a data being accurate with high probability through repeated data reading of a code pattern on a film cartridge even in hard conditions, such as a condition where contact between contact terminals of the device and code regions of the code pattern is unstable and a condition where the resistance value of a conductive code region is comparatively high or varies with the area on which the corresponding contact terminal abuts. In one operation example of an embodiment, the device discriminates consistency and inconsistency between the contents of the successively read data bit by bit and substitutes the contents of the later read data discriminated as being inconsistent for those of the previously read data only when the inconsistency discriminated contents of the later read data indicate conduction of the corresponding code regions. The previously read data is thus renewed again and again so as to more accurately correspond to the data indicated by the code regions of the code pattern.