A rolling element including a base metal, and a nickel coat formed on a surface of the base metal and cooperating with the base metal to constitute a rolling contact surface satisfying condition that a mean value of ratios of L1 to L2 as measured in at least three optional observation areas is in a range of from 1.2 to 2.4, where each observation area is disposed in a cross section taken in a vertical direction relative to the surface of the base metal and is defined by two parallel vertical lines; lengths L1 and L2 respectively represent a length of an interface between the base metal and the nickel coat, and a length of a reference line segment extending perpendicular to the vertical direction, in same observation area.