An ultrasonic device includes a base, a plurality of ultrasonic transducer elements, an acoustic adjustment layer, and a wall part. The ultrasonic transducer elements are arranged in an array form on the base, each of the ultrasonic transducer elements having a vibration film. The acoustic adjustment layer is disposed on each of the ultrasonic transducer elements. The wall part is arranged between adjacent ones of the ultrasonic transducer elements when viewed in a plan view along a thickness direction of the base such that the acoustic adjustment layer on the adjacent ones of the ultrasonic transducer elements are separated by the wall part in a range of at least a portion of a height of the acoustic adjustment layer measured from the base. The wall part has an acoustic impedance that is higher than an acoustic impedance of the acoustic adjustment layer.
