Abstract: A glass substrate for a magnetic recording medium is formed to have a disc shape and includes ridge shaped textures 13 extending along concentric circles on a main surface. When measuring a 10 ?m square range with an atomic force microscope, the textures have a width W that is between 10 and 200 nm. The textures have a height H that is between 2 and 10 nm. Further, the textures have a ratio (Rp/RMs) of a maximum mountain height with respect to a root mean square roughness that is less than or equal to 15. The textures include high frequency components superimposed on the low frequency components. It is preferable that the textures of the high frequency components have a width W? that is between 0.1 and 20 nm, and the textures of the high frequency components have a height H? that is between 0.1 and 1 nm.

Abstract: A glass substrate for a magnetic recording medium is formed to have a disc shape and includes ridge shaped textures 13 extending along concentric circles on a main surface. When measuring a 10 ?m square range with an atomic force microscope, the textures have a width W that is between 10 and 200 nm. The textures have a height H that is between 2 and 10 nm. Further, the textures have a ratio (Rp/RMs) of a maximum mountain height with respect to a root mean square roughness that is less than or equal to 15. The textures include high frequency components superimposed on the low frequency components. It is preferable that the textures of the high frequency components have a width W? that is between 0.1 and 20 nm, and the textures of the high frequency components have a height H? that is between 0.1 and 1 nm.

Abstract: A sputtering apparatus comprises a chamber in which at least one object to be deposited by a film is movably provided; a plural sets of cathodes are arranged in the chamber, each set consisting of two cathodes positioned side by side and having an opposite polarity; and a plurality of AC cathode power supplies each connected to corresponding one set of cathodes for generating alternating voltages, frequencies and phases thereof are synchronized so that discharges by means of respective sets of cathodes do not interfere to each other when the alternating voltages are supplied to the cathodes to cause discharges at the same time. To the plural sets of cathodes are supplied alternating voltages whose frequencies and phases are synchronized respectively from the plurality of AC cathode power supplies. Therefore, a discharge is not unstably fluctuated when the plural sets of cathodes generate discharges at the same time.