Abstract: Top-hat quadric spherical electrostatic analyzer with a collimator is of large advantage over the bare analyzer (without collimator). The simulation program for the bare analyzer has been already set up successfully[1]. The new simulation program has been developed from the modifications of that for the bare analyzer. These modifications are not significant and substantial, since the difference between two analyzers is only in the structure configuration at entrances, with/without collimator. In effect, the simulation procedures and techniques used in two programs are also similar to each other basically. In addition, the program is applied to a sample of top-hat analyzer with a collimator. The simulation results generated from the program are also reported in this paper.