An ultrasonic probe includes an ultrasonic transducer which is formed by sequentially laminating an acoustic lens, an acoustic matching layer, a piezoelectric element, and a backing member. The backing member arranged on a surface opposed side of the acoustic matching layer and the acoustic lens arranged to the piezoelectric element contains a synthetic rubber containing a mixture including acrylonitrile-butadiene rubber (NBR), ethylen-propylene terpolymer (EPDM), and at least inorganic fine powders.