The present invention provides a portable ultrasonic diagnostic apparatus including an ultrasonic probe which transmits ultrasonic signals to a subject and then receives echo signals reflected from the subject, a beamformer which collects the echo signals and generates frame data, a scan conversion portion which scans and converts the frame data and forms ultrasonic images, a display portion which displays the ultrasonic images, a memory which stores image data on an image when ultrasonic diagnosis is not performed, an ultrasonic image comparative analyzer which compares and analyzes the ultrasonic images of the display portion and the image data stored in the memory, and a low power mode control portion which enables the whole circuit to enter a low power mode when it is determined that an ultrasonic image displayed on the display portion is an ultrasonic image of a case in which ultrasonic diagnosis is not performed.
