Electric power transformers are a very important parts of a modern electric power system and they consider as a high level source of electromagnetic fields which can effect the health of workers in station. In this research, electric and magnetic fields caused due to the operation of power distribution substation of 132/33 kV are investigated in order to avoid the overexposure of these fields to workers. Research was performed on both the mathematical calculations and practical measurements. The intensities of electric and magnetic fields have been calculated based on the Maxwell's equations and measured at substation by tester device. Safe zones from some equipment have been determined .Comparison the obtained results with the standard safety guideline limits shows that they are within the acceptable expositing limits recommended by the world health organization. That means there is no health risk from exposure to these fields if the exposure is for a short and discrete periods.