Cyclotrons are one of the circular accelerators, which uses electrical field to accelerate the particle and the magnetic field to confine its path in a circular way. This machine is usually used to accelerate the proton and the helium nuclei. The main parts of these kind of accelerators are, electromagnet, radiofrequency system, vacuum and the ion source. Recently, in the Isfahan University of Technology, building a cyclotron is in progress, with cooperation between central laboratory and physics department. The main aim of this thesis is to design some parts of the machine and simulate its electrical and magnetic fields and the particle's dynamics. The vacuum chamber and its flanges were designed, then they were constructed. The mean free path of a proton in hydrogen gas and the needed vacuum pressure was calculated, then we had a review on the methods of making vacuum and measuring it. By solving the particle equations, its path in the X-Y directions was determined and by using that, estimated values of some important parameters were obtained, such as the radius of the chimney. The electrical field in the vacuum chamber was simulated using the Poisson/SuperFish code, then designing the inside of the chamber components was optimized. We had a review of the cyclotron's radio frequency system. Effects of the RF voltage on the particle acceleration were analyzed, and finally the magnetic field was simulated completely using PSF and SF7, then their effects on the particle motion and its stability were analyzed. Keywords : Cyclotron, Electromagnet, Ion source, Radio frequency system, Mean Free Path, Chimney, Poisson/SuperFish, SF7