Most phantom models do not include distinct definitions of tumor and normal tissue. This article proposes a novel solid breast - tumor phantom for microwave hyperthermia in breast cancer treatment. According to tissue dielectric properties reported, we performed phantom. A Network Analyzer and Dielectric Probe Kit measured dielectric constant and electrical conductivity for both breast normal tissue and tumor phantom. Measurements were through at frequency range from 2 to 3 GHz due microwave operation frequency is usually 2.45 GHz. At 2.45 GHz breast phantom had an electrical conductivity of 0.1304±0.0680 S/m and a dielectric constant of 4.4401 ± 1.2514. At the same frequency, tumor phantom had an electrical conductivity of 2.7015 ± 0.0783 S/m and a dielectric constant of 55.2566 ± 1.1899. The presented results highly correlate with the expected values. Therefore this phantom can be used for microwave hyperthermia in breast cancer treatment and antenna performance analysis and optimization.