Disclosed is an ultrasonic diagnostic apparatus including an improved actuator to compensate for a weight of an input/output device. The ultrasonic diagnostic apparatus includes a main body, an input/output device coupled to the main body and configured to receive information from a user or output information received from the main body, and a connection device to connect the main body and the input/output device, wherein the connection device includes a shaft having a shaft body, a link frame having a frame body and a shaft coupling portion extending from the frame body to be coupled with the shaft, and an actuator including a torsion spring having a first end supported by the shaft and a second end supported by the link frame, so as to compensate for a weight of the input/output device.
