A magnetic head assembly of the present invention includes a head rail having a plurality of head element portions each including a MR element and sliding portions that come into contact with a magnetic tape, and a protective film on a magnetic tape sliding surface of the head element portions and the sliding portions, wherein the protective film is formed in a portion other than the vicinity of both ends of the head rail in a traveling direction, and an outermost surface of the protective film, on which a magnetic tape is capable of sliding, is formed flat. Thus, a magnetic head assembly used in a magnetic tape apparatus can be provided, in which an output does not decrease due to the abrasion deformation of the head element portions and the increase in spacing by the adhesion of stain.