To provide an ultrasonic wave transmitting apparatus, in which a beam width in a two-dimensional direction (direction of the length of piezoelectric elements) is made into specified value within a predetermined distance, and the beam width is reduced to enhance sharpness or fidelity, by providing an ultrasonic propagation body.

In the ultrasonic beam trasmitting apparatus for sending ultrasonic waves to be converged in a two-dimensional direction from the front face of a piezoelectric element group, wherein a plurality of piezoelectric elements are arranged in a one-dimensional direction, the front face of the piezoelectric element group comprises an ultrasonic propagation body, wherein the width in the two-dimensional direction is reduced towards the side of a distal end.