An ultrasonic diagnostic apparatus comprising: a generating unit (20, 22) configured to generate a frame sequence by repeating generation of transmitting signals and processing of received signals according to a plurality of transmission/reception conditions that are alternated cyclically for the frames of the frame sequence; and a synthesizing unit configured to generate a synthesized frame sequence from the frame sequence, the synthesizing unit comprising an added frame generator for generating, for each of frame sets in the frame sequence, an added frame, an edge-enhanced frame generator for generating, for each of frame sets in the frame sequence, an edge-enhanced frame, and a synthesizer for synthesizing the added frame and the edge-enhanced frame such as to generate a synthesized frame based on a plurality of frames forming each frame set, a calculating unit configured to calculate an evaluation value as a sum of differences between the added frame and the edge-enhanced-frame over the entire frames; and a control unit configured to change a combination of a plurality of transmission frequencies included in the plurality of transmission/reception conditions based on the evaluation value; wherein: the plurality of transmission/reception conditions comprise a first transmission/reception condition for a close range and a second transmission/reception condition for a long range, the first transmission/reception condition includes a first transmission frequency and a first transmission depth of focus, the second transmission/reception condition includes a second transmission frequency that is lower than the first transmission frequency and a second transmission depth of focus that is greater than the first transmission depth of focus, and the control unit is configured to change the combination of the first and second transmission frequencies based on the evaluation value. a generating unit (20, 22) configured to generate a frame sequence by repeating generation of transmitting signals and processing of received signals according to a plurality of transmission/reception conditions that are alternated cyclically for the frames of the frame sequence; and a synthesizing unit configured to generate a synthesized frame sequence from the frame sequence, the synthesizing unit comprising an added frame generator for generating, for each of frame sets in the frame sequence, an added frame, an edge-enhanced frame generator for generating, for each of frame sets in the frame sequence, an edge-enhanced frame, and a synthesizer for synthesizing the added frame and the edge-enhanced frame such as to generate a synthesized frame based on a plurality of frames forming each frame set, an added frame generator for generating, for each of frame sets in the frame sequence, an added frame, an edge-enhanced frame generator for generating, for each of frame sets in the frame sequence, an edge-enhanced frame, and a synthesizer for synthesizing the added frame and the edge-enhanced frame such as to generate a synthesized frame based on a plurality of frames forming each frame set, a calculating unit configured to calculate an evaluation value as a sum of differences between the added frame and the edge-enhanced-frame over the entire frames; and a control unit configured to change a combination of a plurality of transmission frequencies included in the plurality of transmission/reception conditions based on the evaluation value; wherein: the plurality of transmission/reception conditions comprise a first transmission/reception condition for a close range and a second transmission/reception condition for a long range, the first transmission/reception condition includes a first transmission frequency and a first transmission depth of focus, the second transmission/reception condition includes a second transmission frequency that is lower than the first transmission frequency and a second transmission depth of focus that is greater than the first transmission depth of focus, and the control unit is configured to change the combination of the first and second transmission frequencies based on the evaluation value. the plurality of transmission/reception conditions comprise a first transmission/reception condition for a close range and a second transmission/reception condition for a long range, the first transmission/reception condition includes a first transmission frequency and a first transmission depth of focus, the second transmission/reception condition includes a second transmission frequency that is lower than the first transmission frequency and a second transmission depth of focus that is greater than the first transmission depth of focus, and the control unit is configured to change the combination of the first and second transmission frequencies based on the evaluation value.