In an ultrasonic probe including an insert section which is to be inserted into a body cavity organ of a subject and a handle section which is coupled with the insert section, a plurality of vibrator elements (104) are disposed at a tip end of the insert section over the entire 360 degree circumference thereof and in the handle section, a connection change over switch (105) is disposed which successively changes over the electrical connection of a predetermined number of the vibrator elements among the plurality of the vibrator elements to be connected with a predetermined number of ultrasonic wave transmission and reception channels (701,702) in an ultrasonic diagnostic apparatus main body for transmitting and receiving ultrasonic wave signals. Accordingly, an ultrasonic probe which permits to collect ultrasonic wave images including tomograms and blood flow images of high quality without positional irregularity over the entire circumference of the insert section of the ultrasonic probe and to display the same, and an ultrasonic diagnostic apparatus using the same are obtained.