Method for judging coercive force of magnetic recording medium

A method for judging a coercive force of a magnetic recording medium in order for recording magnetic information to be formed in either a low coercivity magnetic medium or a high coercivity magnetic medium by using a magnetic head, the method comprising:

• a magnetic information recording step comprising writing magnetic information in the magnetic recording medium by alternately using a first write current, suitable for writing in the low coercivity magnetic medium and a second write current, suitable for writing in the high coercivity magnetic medium;
• a magnetic information reproducing step comprising reproducing the magnetic information written in the magnetic recording medium;
• and
• a judging step comprising making a judgment on a coercive force of the magnetic recording medium by way of comparing a first reproduced output of the magnetic information written with the first write current and a second reproduced output of the magnetic information written with the second write current.