A magneto-hydrodynamic simulation of plasma focus device with hemisphere electrodes is constructed. The snowplow model is used with help of the momentum conservation equation to describe the motion of the plasma sheath between the two concentric hemispheres. The model simulates various plasma parameters like plasma temperature and plasma sheath velocity. The circuit equation is used to calculate the discharge current and electrodes voltage across the two hemi spheres terminals. A comparison between the cylindrical and spherical devices is built. The results show that the current dip and spike voltage is expected to be much pronounced in the spherical devices. It is found also that the plasma sheath velocity and temperature in the case of the cylindrical system are higher than that in the spherical one.