A diagnosis apparatus encompasses a probe array (1, 2) made of material having electromagnetic characteristic identical to the electromagnetic characteristic of a target object, the probe array (1, 2) embraces a receptacle 1 having a semispherical inner wall surface, and a plurality of antennas 2, arranged along the inner wall surface, the plurality of antennas 2 carry out electrical measurement of a target region in the target object, a fixing mechanism configured to cover whole of the target region with the probe array (1, 2), bringing skin of the target region into close contact with the inner wall surface, so as to fix a relative position between the target region and the probe array (1, 2), and a measuring, controlling and analyzing mechanism configured to control the plurality of antennas 2, to execute the electrical measurement, and to analyze a data based on the electrical measurement so as to detect an abnormal cell in the target region. The diagnosis apparatus has a high contrast and a high resolution and does not suffer from any X-ray exposure and is low in diagnosis cost and safe, sure, comfortable and high in speed and high in reliability.