A device for measuring electrical current, voltage and temperature in a conductor made of rigid material is disclosed. The conductor is formed from two conductor sections, between which an electrical resistor element is provided that is made of a material having greater resistance than the material of the conductor sections. In the region of the resistor element, a flattened area with a depression is provided, over which a measuring arrangement, through which a portion of the current flowing through the conductor flows, is placed in the manner of a bridge. In the measuring arrangement is arranged in the vicinity of a contact piece by means of which the conductor can be connected in an electrically conducting manner to another conductor such that the heat generated at the contact point is measured.