The device for isothermal stamping includes upper and lower base plates, a stamp, a heating and a heat-insulating block. The stamp block consists of upper and lower stamp halves, each of which is mounted in a stamp holder and provided with thermal insulation elements, the heating block is made of heating elements located on the sides of the stamp block. Additionally, in the stamp holders, the stamp halves are fixed with quadrangular wedge-shaped rods and mounted on heatresistant sub-stamp plates with heating elements mounted therein. The heating elements are connected in a series electrical circuit with the heating elements of the heating unit and have the same cross-section as them, and the heat-insulating unit is made of a two-chamber, divided support body and consists of an outer set of detachable heat-insulating covers and an inner heat-insulating cover in which the heating unit is installed, the support body is equipped with a mechanical unit for lifting the inner heat-insulating cover and the upper part of the detachable outer cover with the possibility of providing.