Provided is an electromechanical transducer device including a substrate that is conductive, and a plurality of electromechanical transducer elements disposed on a first surface of the substrate. A groove that electrically isolates the plurality of electromechanical transducer elements from each other is formed in the substrate, the groove extending from a second surface side of the substrate toward the first surface side of the substrate, the second surface being opposite the first surface. The width of the groove on the first surface side of the substrate is smaller than the width of the groove on the second surface side of the substrate.