Provided is a processing device for a medium, which is capable of processing a recording medium at a high speed and which is capable of miniaturization of the device in a transport direction for the recording medium. This processing device for a medium (1) is provided with magnetic heads (24, 26, and 28) which face a medium transport channel (13) from a lower side, magnetic heads (25, 27, and 29) which face the medium transport channel (13) from an upper side, pad rollers (45 to 50) which are disposed so as to face each of the magnetic heads (24 to 29), a movement mechanism (51) for evacuating pad rollers (45, 47, and 49) from the medium transport channel (13), and a movement mechanism (52) for evacuating pad rollers (46, 48, and 50) from the medium transport channel (13). In the transport direction for the recording medium, the magnetic head (24 (as well as 26 and 28)) and the magnetic head (25 (as well as 27 and 29, respectively)) are offset from each other, and the distance between the magnetic head (24 (as well as 26 or 28)) and the magnetic head (25 (as well as 27 or 29, respectively)) in the direction is shorter than the length of the range for recording of magnetic data recorded upon a magnetic stripe of the recording medium.