The conclusion about the absence in them of the mathematical means of the adequate description of passage from one inertial reference system to another because of the use by them of particular derived field functions on the time, which completely tie electrodynamic process to one concrete frame of reference, is made on the basis of the critical analysis of extraction from the equations of the electrodynamics of ideas about the space and period. Is proposed new approach to the development of the mathematical apparatus for electrodynamics in the direction of the more adequate description of passage from one inertial reference system to another due to the introduction into the examination of the trans-coordinate equations, which use new Galilean and trans-coordinate derivatives of field functions. This generalization of electrodynamics assumes the dependence of electromagnetic field and electric charge on the speed of the motion of observer, caused not by the geometry of space-time, but by physical nature of the very field within the framework of gipercontinual ideas about the space and the time. Is obtained the new trans-coordinate formulation of Maxwell equations for the case of isotropic homogeneous medium without the dispersion, which generalizes the traditional formulation of Hertz-Heaviside for the same case. Are given Maxwell equations in the integral and differential forms in the idea of Hertz-Heaviside and in the transcoordinate idea