The industrial applications of a single tank system are widely used especially in the food process industries. A control of liquid level in a tank is a problem in the process technologies. The accurate control of liquid level effects on the product quality and efficiency, as well as its effect on the safety of the production process. This work proposes the digital controller to maintain and regulate a desired liquid level in the tank. A mathematical model of the single tank system was built in the MATLAB Simulink. The control design method is demonstrated and verified in simulation and experimental environments. Based on the performance of the system in terms of desired liquid level, rise time, settling time and steady state error, the results show that the proposed method of the digital control design gives simple and effective controller for liquid level system. This technique can be easily embedded in the real tank system. Keywords: Tank system, Digital control, and P-controller