Cancer is one of the biggest causes of death in recent years. Different methods are used to identify and separate cancer cells from blood. One of the best and most complete separation methods is separation by acoustic waves. In fact, in this method, with an electrical energy input, Rayleigh waves are applied to the particles in the channel, causing them to move to certain lines and actually separation takes place. In this project, an explanation of the above mentioned technique is presented, while it is used in three-dimensional project,a three- dimentional simulation of the above mention technique is presented. By using the simulation done in COMSOL Multiphysics, all important parameters affecting the forces (aaplied on the cells) are studied. These parameters are; the distance between the interdigital transducers of each other, the length of the interdigital transducers and the number of fingers. In the model, optimized amount of parameters were obtained while the minimum electrical energy input applied. Then the separation of breast cancer cells form white blood cells was simulated. The results show that with that minimum electrical energy, where the input parameters were optimized, separation took place in an optimized manner. Cancer, 3-D Simulation, Acoustic Waves, Cancer cell separetion.