In this research, an optical system is made and aims for Faraday rotation apparatus. This system was designed and made to measure the rotation angle of plane of polarization on analyzer, light intensity, and value of magnetic field, where as the analyzer angle setting is done by using a stepper motor which connected to the lens of analyzer by a gear set, for the light intensity the writer measured it with a lux meter IC BH1750, and the magnetic field measured based on the current which given by constant current power supply. Number of pulses on the stepper motor and the data from the IC BH1750 is being acquired using a microcontroller. In this research, the writer used two variable wave length from different color on 30 watt LED as the light sources, all of these light sources are being controlled by the microcontroller. Based on this research, the writer conclude that there are transfer function (p= 17.832θ), where (θ) is the rotation angle of analyzer and (P) is the pulse that is generated from the stepper motor. All of the control system is controlled by a microcontroller that is integrated with the computer.