A metal part in which a base material of silicon-aluminum alloy having 1 to 25% by mass of silicon as an anode is immersed in an electrolyte together with a cathode, and at least a portion of a surface of the base material is anodized and coated with an anodic oxide film. A current density provided to both the anode and the cathode is increased from an initial current density of 0 A/dm2 at a rate between 0.15 and 0.35 A/dm2 per minute, wherein once the current density reaches a prescribed current density of between 0.8 A/dm2 and 1.2 A/dm2, the current density provided to the anode and the cathode is maintained at the prescribed current density.