An ultrasonic probe includes a multi-dimensionally arrayed transducer, a matching layer, and a backing layer. The transducer includes element groups having different focal distances and simultaneously transmitting ultrasonic signals toward an object. According to the ultrasonic imaging apparatus using the multi-dimensionally arrayed transducer, a multi-focus transmission is performed. Thus, the multi-focus ultrasonic image may be acquired within a short period of time, thereby increasing frame rates, and a high-quality image in which all areas are focused may be quickly acquired.