A relay device includes: an electromagnet constituted by a metallic core and an electrical winding associated therewith; and a mobile anchor associated with a traction spring and suitable for oscillating around a respective axis of oscillation in response to the combined action of an electromagnetic attraction force, generated by the electromagnet and intended to attract the anchor towards the core, and an elastic recovery force, exerted by the spring and intended to move the anchor away from the core and make it return to an initial position, so as to open or close selectively via the anchor a contact or switch of an external electrical circuit, wherein the anchor has a balanced or equilibrium configuration in which its centre of gravity is arranged substantially along the axis of oscillation, and thereby the masses of various portions anchor portions are distributed in a balanced manner around the same axis of oscillation.