Ultrasonic apparatus that automatically adjusts the focus of ultrasonic waves to a desired depth within an object includes an ultrasonic probe which irradiates a focused ultrasonic beam onto an object to be inspected and a receiver which receives ultrasonic waves reflected from the object. A desired focusing depth is set and the inherent focal length of the probe and the velocity of sound within the object are detected to evaluate a distance between the probe and the object at which the focus of the probe coincides with the desired depth. The distance between the probe and the object is adjusted to coincide with the evaluated distance.