PURPOSE: To provide a magnetic card of a comparatively simple and new constitution which is effective to prevent its forgery.

CONSTITUTION: This magnetic card consists of a magnetic recording layer 12 which is made of a magnetic material and formed at least at a part of a substrate and a heat expandable layer 13 which is made of a heat expandable non-magnetic material and formed at least at a part on the layer 12. The regular signals having the fixed regularity are magnetically recorded over a prescribed area of the layer 12 formed under the layer 13. Meanwhile an expanding part 13a which has the thickness larger than the prescribed value when it is heated in a prescribe pattern shape is formed in a prescribed pattern shape on the layer 13 and at least at a position over the area where the regular signals are recorded. Thus a pattern signal can be read on the surface of the layer 13 in response to a prescribed pattern and by the difference between the reproduced output of the regular signal produced via the part 13a and the reproduced output of the regular signal produced via a non-expanding part.