A supersymmetric grand unified model based on SU(5) is constructed. As a candidate to the solution of gauge hierachy problem, the scale of supersymmetry breaking is hypothesized as ordinary mass scale of order $10^2 GeV$. By spontaneous (SU(5)) gauge symmetry breaking using Higgs field at energy $M_{GUT}$ (order of $10^{15} GeV$), the superheavy vector bosons get mass of order $M_{GUT}$. And due to supersymmetry breaking at energy $M_W$ (order of $10^2 GeV$) the gauge bosons $W^+,\; W^-$ and Z and their scalar and spinor partners acquire masses of the order $10^2 GeV$, and the gauge hierachy problem gets a natural solution.