A portable ultrasonic diagnostic device comprising: a transducer which generates and emits an ultrasonic pulse from an applied electrical pulse toward an object to be inspected and receives an echo signal therefrom; and a main circuit portion which generates an electrical pulse to be applied to the transducer, generates scan line data from the echo signal, and transmits frame data including a certain number of scan line data to a portable terminal, characterized in that: the main circuit portion transmits, using a wireless communication method, the scan line data or the frame data during a time except a reception time of the echo signal and generates the electrical pulse during a time except a transmission time of the frame data, wherein the main circuit portion transmits the frame data when a reception time of an echo signal for the last scan line, which forms a frame, is completed, and generates an electrical pulse for the first scan line of the next frame when the frame data is completely transmitted, and wherein the main circuit potion comprises: a pulse generator which generates the electrical pulse; a beam former which generates the scan line data by beam-forming the echo signal; a buffer which stores the generated scan line data; and a processor which transmits frame data including a certain number of the scan line data stored in the buffer, wherein the processor transmits the frame data when the reception time of the echo signal for the last scan line is completed, and wherein the pulse generator generates the electrical pulse for the first scan line of the next frame when the frame data is completely transmitted. a transducer which generates and emits an ultrasonic pulse from an applied electrical pulse toward an object to be inspected and receives an echo signal therefrom; and a main circuit portion which generates an electrical pulse to be applied to the transducer, generates scan line data from the echo signal, and transmits frame data including a certain number of scan line data to a portable terminal, the main circuit portion transmits, using a wireless communication method, the scan line data or the frame data during a time except a reception time of the echo signal and generates the electrical pulse during a time except a transmission time of the frame data, wherein the main circuit portion transmits the frame data when a reception time of an echo signal for the last scan line, which forms a frame, is completed, and generates an electrical pulse for the first scan line of the next frame when the frame data is completely transmitted, and wherein the main circuit potion comprises: a pulse generator which generates the electrical pulse; a beam former which generates the scan line data by beam-forming the echo signal; a buffer which stores the generated scan line data; and a processor which transmits frame data including a certain number of the scan line data stored in the buffer, a pulse generator which generates the electrical pulse; a beam former which generates the scan line data by beam-forming the echo signal; a buffer which stores the generated scan line data; and a processor which transmits frame data including a certain number of the scan line data stored in the buffer, wherein the processor transmits the frame data when the reception time of the echo signal for the last scan line is completed, and wherein the pulse generator generates the electrical pulse for the first scan line of the next frame when the frame data is completely transmitted.