The method and the device for detecting flaws in materials and their connections comprise the radiation of ultrasonic rays and the reception of that energy after its reflection from the examined product, wherein the component which creates, radiates and receives the ultrasonic energy is comprised of a number of interconnected sub-plates. The focused energy which penetrates the metal has a special form appropriate to the type and shape of the product. The sub-plates are mechanically connected to a cylindrically-shaped base, and electrically interconnected by adjustable electronic control means which appropriately change the characteristics of the sub-plates when necessary. The bases of each sub-plate system are made of a material transparent to ultrasonic rays, for example plastic, and the contact surfaces of the bases of each of the sub-plate systems are fortified by grooves filled with a wear-resistant material. The shape of the base edge of each of the sub-plate systems is that of cylindrical surface section each sub-plate system is installed on the edge of one base and its shape is close to the shape of the base's cylindrical section surface. The surface of the base edge of each of the sub-plate systems is positioned at some angle relative to the contact surface of that base. One version of the device for detecting flaws in materials and their connections comprises two separate converters, each with its own cover and both connected into one unit by means of a holder and bridges. The connection between one of the converters, for example the radiator, and the holder, is made by means of a fixed bridge, while the connection between the second converter, for example the receiver, and the holder is established by means of a bridge with a hinge which allows limited movement.