1. A diagnosis image generating apparatus comprising: a plurality of probes comprising at least one transducer configured to transmit a signal to an imaging target object and receive an echo signal reflected from the imaging target object; a detector configured to detect information regarding the imaging target object from the echo signals received by the plurality of probes; a selector configured to select a probe which receives the echo signal from which information regarding the imaging target object is detected from among the plurality of probes; and a diagnosis image generator configured to generate a diagnosis image of the imaging target object by using a selected probe, wherein the selector automatically selects a probe that is contacting or close to the imaging target object from among the plurality of probes.