In this paper, the half-life values of spherical proton emitters such as Sb, Tm, Lu, Ta, Re, Ir, Au, Tl and Bi have been calculated within the framework of fractional calculus. Nuclear decay equation, related to this phenomenon, has been resolved by using Caputo fractional derivative. The order of fractional derivative mu being considered is 0 < mu <= 1, and characterizes the fractality of time. Half-life values have been calculated equivalent with empirical ones. The dependence of fractional derivative order mu on the nuclear structure has also been investigated.