A serpentine mineral ore was treated in a planetary mill, and sulfuric acid leaching was done to investigate the extraction yield of the metal elements from the milled mineral. The mineral structure was transformed into an amorphous state by milling. It was found that the extraction yield was significantly enhanced. After 240 minutes of milling, Mg and Fe metal elements were leached out at almost 100% from the serpentine within 5 minutes in 1 N $H_2SO_4$ at $^50{circ}C$, while 80% of Ca and 55% of Si and Al were obtained within 10 minutes.