Breast cancer is a mortal disease in the world . The research on this matter is necessary for finding methods to help counteract this disease. Microwaves are used to treat cancer (hyperthermia), to create medical images for diagnose cancer, etc. To treatment to induced superficial hyperthermia are used monopole antennas, microstrip antennas, etc. Monopole antennas are used to create medical images. We work to develop two microstrip antennas. One of them is to get medical image and the other to induced superficial hyperthermia. The first step is the simulation of the antennas with COMSOL 4.0, to know their performance. The purpose is to locate the tumor and then expose it to superficial hyperthermia to diminish the tumor.