An apparatus of the present invention is a magnetic recording /
reproduction apparatus for pulling out a
magnetic tape from a tape cassette and winding the
magnetic tape around a rotary head cylinder, having a rotary head, for a predetermined arc, for recording / reproducing the
magnetic tape. The magnetic recording /
reproduction apparatus includes: a rotary head cylinder; a first base member on which the tape cassette is mounted; a second base member for guiding a reciprocal movement of the first bane member toward / away from the rotary head cylinder; first to fifth vertical posts for guiding the magnetic tape, wherein a winding
contact line, along which the magnetic tape contacts each of the first to fifth vertical posts, is perpendicular to a tape driving direction in which the magnetic tape is driven; and first to third inclined posts for guiding the magnetic tape, wherein a winding
contact line, along which the magnetic tape contacts each of the first to third inclined posts, is not perpendicular to the tape driving direction.