The purpose of the present paper is to investigate mapping properties of an integral operator in which we show that the function g defined by $$g(z)={frac{c+{alpha}}{z^c}{int}_{o}^{z}t^{c-1}(D^nf)^{alpha}(t)dt}^{1/{alpha}}$$. belongs to the class $S(A,B)$ if $f{in}S(n,A,B)$.