Partial discharge is an instantaneous energy release depending on a charge accumulation caused by an electric field localized in any section of insulation materials. In this phenomenon, there is no observation of full discharge but electrical perforation and damage in insulation materials can be occurred. Traditional measurement method of partial discharge is based on partial discharge detectors which are defined in IEC 60270 standard. This standard also defines partial discharge calibrators which are used for calibration of partial discharge detectors. This paper explains the design, construction and calibration of a simple partial discharge calibrator. Main idea of the design is based on generating fast rising and slow falling voltage pulses from digital to analog converter of an ARM7 based microcontroller. These voltage pulses are applied to a capacitor where they become charge pulses. Complete design was constructed in an aluminium case and the calibrator’s performance was evaluated. Results showed that the designed calibrator is fully compatible with IEC 60270 standard.