Microwave imaging is recognized as a potential candidate for biomedical applications, such as breast cancer detection. In this context a miniature antenna is used for quantitative imaging of inhomogeneous tissues. Microwave breast imaging (MBI) uses low power and longer wavelength signals to obtain information about breast tissues, and promises a safer and more accurate modality for regular breast scanning. This paper presents a miniature microstrip antenna that can be placed in contact with the breast model to investigate the presence of malignant tissues. A miniature antenna has been designed, and placed toward a breast phantom model with inhomogeneous tissues. Images are successfully obtained by using scattering electromagnetic waves (S11) from the designed model. The antenna was then manufactured and tested. In this paper the design of a miniature antenna for microwave imaging has been presented. This antenna aims to overcome the limitation of the conventional solutions by detecting breast tumors regardless its evolution stages. The simulation results show that the response of the antenna is affected in terms of frequency and return loss when it’s implanted on the heterogeneous model. Indeed, comparing to the normal breast model simulated response, the frequency was down shifted of around 100 MHz and the S11 parameter was improved. The antenna has been fabricated using plexyglass substrate and the measured results confirm the resonance frequency shift from 2.63 GHz to 2.54 GHz and the S11 improvement from -12 dB to -18 dB These results are respectively obtained when the antenna is implemented on two different mediums: clean serum representing a human body with absence of tumor and serum with steel balls representing human body with presence of tumor. After this first proof-of-concept, it’s intended to design the antenna using a flexible substrate and to perform real tests using samples representing tumors in human body which would be given by the research team of CHRU (Centre Hospitalier Régional et Universitaire de Brest) in Brest - France.