To set inhibition or release of writing, so that a user can easily understand it, without complicating the constitution of a recording medium.

At first, a CPU 112 detects the insertion of a memory card 40 to a second position P2 (S11). Specifically, when a terminal 43 for data contacts a first terminal 22a and a terminal 44 for detecting the writing contacts a second terminal 22b, the first and second terminals 22a, 22b are electrically conducted. The level of the potential of the first terminal 22a becomes low (L level) same as the ground. The CPU 112 releases (S12) the inhibition of data writing to the memory card 40, when the potential of the first terminal 22a is detected as being at L level.