The application of Noetrs theorem as a method for obtaining the conservation law is considered in this paper. The property of invariation of the variation principles is used, i. e. the invariation of Lagrange in relation to the family of the infinitesimal transformations is used for obtaining the general form of the conservation law for scalar and vector fields. For the concrete example the thermo-elastic dielectric is taken, and by using Noether's inversion theorem the corresponding families of transformations and in addition to therm the corresponding laws conservation are derived.