It is an object of this invention to provide an FPC capable of improving tamper resistance. An FPC (1) of this invention includes: a signal line pattern (2) for inputting a communication signal; and signal protective line patterns (3, 4) provided to be opposed to an upper surface and a lower surface of the signal line pattern and having the same width as a width of the signal line pattern (2) or a larger width than the width of the signal line pattern (2). The signal protective line patterns are provided along the signal line pattern within a region that requires tamper resistance.