To enhance the accuracy of magnetic data processing when reading or writing data from or to a magnetic stripe on a medium.

This magnetic stripe data processing apparatus includes a magnetic head 28 for processing the magnetic data of the medium 18 having the magnetic stripe 12; a plurality of conveying rollers 30-34 and a plurality of #1-#5 pinch rollers 35-39 provided near and in front of and behind the magnetic head 28; a conveying motor 40 for conveying the conveying rollers 30-34; a pinch roller drive part 70 for moving the #1-#5 pinch rollers 35-39 into contact with or away from the medium 18; a magnetic head drive part 72 for moving the magnetic head 28 into contact with or away from the magnetic stripe 12; a medium sensor 27 for detecting the position of the medium 18; and a control part 60 for controlling the pinch roller drive part 70 and the magnetic head drive part 72 by conveying the medium 18 to a predetermined position according to the detection of the medium 18 by the medium sensor 27. The magnetic data of the magnetic stripe 12 is processed using the magnetic head 28.