[en] Results of numerical calculation by the finite-difference method of self-consistent problem of the motion of dense ele-- ctron bunch in inhomogeneous cavity is discussed. The pulsed accelerating field with finite storage of energy, excited secondary and induced Coulomb fields affects the bunch. The next problems are considered: in the first case the motion of bunch starts from instable equilibrium in the centre of cavity, in the second it flies into the cavity through the end wall of one of the branch pipes with relativistic initial energy. The energy balance in the dynamic system ''bunch plus total electromagnetic field'' is considered. The changes in laws of bunch motion for the cases when accelerating field or action of intrinsic field ''switch off'' are compared