In this paper, we have studied the electron-donor atom diamagnetic susceptibility confined in a hemi-cylindrical quantum dot (QD). It is analyzed specifically how the impurity location affects diamagnetic susceptibility. The 3D Schrödinger equation in hemi-cylindrical QD was solved using the finite difference method within the effective mass approximation. This is accomplished by performing our system's Hamiltonian in hemi-cylindrical geometry. We have demonstrated that the hemicylindrical size and impurity position have a significant impact on the diamagnetic susceptibility. When the impurity is localized in the center of the nanostructure for the hemi-cylindrical QD, the diamagnetic susceptibility reaches its greatest value.