Humidity affects product quality as well as human comfort. An experimental setup for humidifying process was developed and a suitable black box model is identified for the process. A Fuzzy Logic Controller (FLC) is designed for this process with rule base based on Internal Model Control Proportional Integral technique (IMCPI). FLC was simulated in the MATLAB environment for the humidifying process. By changing the rule base and the number of member ship functions the step response of the system was analyzed. The system showed better performance for higher number of membership functions.