An electromechanical transducer includes a plurality of cells arranged on a substrate, each cell having a first electrode and a second electrode disposed opposite to the first electrode with a gap interposed between them. A plurality of elements, each including at least two cells with their first electrodes or second electrodes electrically connected to each other, are arranged in the transducer. Vibration film structures that includes respective vibration films disposed above the substrate with a gap between them are arranged in the intervals which are devoid of elements separating the plurality of elements. With this structure, the non-uniformity of the radiation impedances of the plurality of elements due to the intervals separating the regions where the elements are respectively arranged can be reduced and hence the influence of the intervals separating the elements on the transmission/reception characteristics can also be reduced.