This thesis is about the development of humidity control of the inverter fed induction motor by PIC microcontroller. The PIC (Peripheral Interface Controller) microcontroller is programmed to read humidity sensor and controlling three constant speeds with as off mode. the inverter variable frequency drive is set with three constant frequencies and off mode. The AC motor's speed is then varied with the changes of variable frequency drive. The thesis included the project background, process of project design in programming and hardware design as well as components selection. The program of this project was implemented in assembly language by using MPLAB Integrated Development Environment (IDE) software. The program is transferred to a demonstration board called PICDEM mechatronics board which comes with a built in PIC16F917 microcontroller.