The magnetic storage apparatus has a high reliability at a recording density of 2 gigabits or more per square inch. The longitudinal recording media necessary to realize the apparatus has a low media noise and is immune from the influence of thermal fluctuations. The magnetic storage apparatus has a longitudinal magnetic recording media including a magnetic layer which is formed on a substrate via a multi-layered underlayer; a driver for driving the recording media in a recording direction; a magnetic head including a recording section and a read-back section; a driver for moving the magnetic head relatively with respect to the longitudinal magnetic recording media; and a read/write signal processor for processing input signals to the magnetic head and output signal read-back therefrom. The read-back section of the magnetic head includes a magnetoresistive head. One layer of the multi-layered underlayer in the longitudinal magnetic recording media which is in contact with the magnetic layer has a substantially hexagonal close-packed (hcp) structure and has crystal grains whose c-axes are substantially parallel with the substrate plane.