The speed control of DC motor is very important because most of the motors that are used in industry are DC motor. In some industries like paper mill constant speed of the motor is required at any loading condition. The main aim of our project is to run DC motor at constant speed irrespective of loading conditions. To achieve this, we are employing a Chopper fed DC motor. The motor can be run at any desired speed by changing the duty cycle of the chopper. The duty cycle of the chopper is controlled by the PWM technique. The microcontroller is employed for changing the width of PWM pulses and the corresponding motor speed is shown on LCD. In this project, we are using AT-Mega- 8L microcontroller and chopper in order to run DC motor at a fixed speed. In this paper, the speed control of dc motor has been investigated by the use of an ATmega8L microcontroller. The high-frequency PWM signal is driven by the chopper. The PWM duty cycle is equal to the motor terminal voltage. This work has high feasibility and accuracy according to the economic point of view. The main objective of this system is to achieve a constant speed of DC motor at any loading condition.