To provide a magnetic card processor for preventing the illegal reading of the information of a magnetic card at the time of inserting and extracting a magnetic card.

A roller 7 is installed in the neighborhood of an insertion port 4 of a magnetic card processor 101 so as to be brought into contact with an emboss part 1e projected from a passing magnetic card 1. When the magnetic card 1 is inserted from the insertion port 4, or the magnetic card 1 put into the inside of the main body 2 is ejected to the insertion port 4, the emboss part 1e of the magnetic card 1 is brought into contact with the roller 7, and the moving speed of the magnetic card 1 fluctuates. Also, an impact is added from the roller 7 to the magnetic card 1, and the magnetic card 1 oscillates. Therefore, even when a false card reader is mounted on the front face of the magnetic card processor 101, the illegal reading of the information of the magnetic card by the false card reader is prevented.