A method of treating a surface of a mold. The method includes forming dimples on a surface of a mold by ejecting substantially spherical ejection-particles so as to bombard the surface of the mold. The dimples are formed so as to satisfy a condition defined by the following formula: 1+3.3e−H/230≤W≤3+13.4e−H/1060 wherein W is an equivalent diameter (μm) of the dimples and H is a base metal hardness (Hv) of the mold.