An ultrasonic device includes an ultrasonic transducer that has a vibration film and transmits an ultrasonic wave from a first surface side of the vibration film, an acoustic matching layer that is provided on the first surface side of the vibration film, and an acoustic lens that is provided on the acoustic matching layer on an opposite side to the vibration film, in which the acoustic matching layer is formed of even-numbered layers including a first layer and a second layer having acoustic impedance lower than acoustic impedance of each of the first layer and the acoustic lens, and the first layer and the second layer are disposed in this order toward the acoustic lens from the vibration film, and in which each of the first layer and the second layer has a thickness corresponding to an odd-numbered multiple of λ/4 with a wavelength of the ultrasonic wave as λ.
