An ultrasonic probe includes, a transducer, a substrate includes electrodes formed on a front surface and a back surface and electronic components, first flexible wire substrates connected in such a manner that a first end is connected to the transducer and a second end is connected to a electrode at a side of the front surface of the substrate, second flexible wire substrates connected in such a manner that a first end is connected to the transducer and a second end is connected to a electrode at a side of the back surface of the substrate, and a dummy materials including the same rigidity and thickness as those of the first flexible wire substrate is arranged at a space, adjacent to a electrode at the side of the front surface of the substrate, corresponding to the second end of the second flexible wire substrate.