An ultrasonic transducer and ultrasonic diagnostic apparatus are provided. An ultrasonic transducer includes a substrate including a trench formed in a lower surface of the substrate； and a first element and a second element formed on an upper surface of the substrate and are located adjacent to each other, wherein the trench is positioned between the first element and the second element, wherein the first element and the second element each include a plurality of ultrasonic cells that are two-dimensionally arranged； wherein a first contour line of the first element and a second contour line of the second element, which are adjacent to each other, each form a zig-zag line which are complementary with each other, and the trench is formed in a zig-zag pattern between the first contour line and the second contour line.
