PURPOSE: To enhance abrasion resistance, by subjecting a magnetic film to ion bombarding treatment prior to vapor depositing a higher aliphatic acid or its metal salt on the magnetic film.

CONSTITUTION: A magnetic tape (a) is allowed to travel between rollers 2 located in a vacuum chamber in one direction, voltage is applied to an electrode 4 for ion bombardment, for example, gaseous argon is allowed to ion bombard the magnetic tape face (b) to remove impurities of moisture, dust, or the like on the face (b), and the tape is wound on one of the rollers 2. Then, the tape (a) treated by ion bombardment is allowed to travel in the reverse direction, and a higher aliphatic acid or its metal salt 15, such as stearic acid or lithium stearate or the like lubricant, is vapor deposited onto the magnetic film face (b) from a crucible 14. The ion bombardment may be carried out in an atm. contg. an acidic gas.