An ultrasonic diagnostic apparatus comprising: a transducer configured to perform interconversion between an acoustic wave and an electrical signal and configured to receive echo signals corresponding to a plurality of plane waves from an object; and a transmitter configured to control the transducer so as to allow the plurality of plane waves to be transmitted through a plurality of sub-apertures; a receiver configured to receive electrical signals corresponding to the echo signals via the transducer; wherein the transducer comprises: first transducer elements configured to transmit an up-chirp type plane wave through a first sub-aperture; and second transducer elements spatially separated from the first transducer elements and configured to transmit a down-chirp type plane wave through a second sub-aperture; wherein the transmitter is configured to control the first and second transducer elements to transmit the up-chirp type and down-chirp type plane wave, respectively, wherein a position of the first sub-aperture is different from a position of the second sub-aperture, wherein the receiver is configured to compress the electrical signals corresponding to the echo signals of the up-chirp type plane wave by using a down-chirp signal, and compress the electrical signals corresponding to the echo signals of the down-chirp type plane wave by using an up-chirp signal, and wherein the up-chirp type plane wave and the down-chirp type plane wave are transmitted simultaneously. a transducer configured to perform interconversion between an acoustic wave and an electrical signal and configured to receive echo signals corresponding to a plurality of plane waves from an object; and a transmitter configured to control the transducer so as to allow the plurality of plane waves to be transmitted through a plurality of sub-apertures; a receiver configured to receive electrical signals corresponding to the echo signals via the transducer; wherein the transducer comprises: first transducer elements configured to transmit an up-chirp type plane wave through a first sub-aperture; and second transducer elements spatially separated from the first transducer elements and configured to transmit a down-chirp type plane wave through a second sub-aperture; wherein the transmitter is configured to control the first and second transducer elements to transmit the up-chirp type and down-chirp type plane wave, respectively, wherein a position of the first sub-aperture is different from a position of the second sub-aperture, wherein the receiver is configured to compress the electrical signals corresponding to the echo signals of the up-chirp type plane wave by using a down-chirp signal, and compress the electrical signals corresponding to the echo signals of the down-chirp type plane wave by using an up-chirp signal, and wherein the up-chirp type plane wave and the down-chirp type plane wave are transmitted simultaneously. first transducer elements configured to transmit an up-chirp type plane wave through a first sub-aperture; and second transducer elements spatially separated from the first transducer elements and configured to transmit a down-chirp type plane wave through a second sub-aperture; wherein the transmitter is configured to control the first and second transducer elements to transmit the up-chirp type and down-chirp type plane wave, respectively, wherein a position of the first sub-aperture is different from a position of the second sub-aperture, wherein the receiver is configured to compress the electrical signals corresponding to the echo signals of the up-chirp type plane wave by using a down-chirp signal, and compress the electrical signals corresponding to the echo signals of the down-chirp type plane wave by using an up-chirp signal, and wherein the up-chirp type plane wave and the down-chirp type plane wave are transmitted simultaneously. <EOS>