The hub of a take-up reel (20) has a notch (20b) which is formed so as to correspond to the moving paths of guide posts (33, 34, 35) passing between a rotating drum type magnetic head (10) and the take-up reel (20). With this configuration, the magnetic head (10) and the take-up reel (20) can be disposed close to each other, thereby reducing the plane installation area of a magnetic recording/reproducing apparatus in the longitudinal direction.