Examination has been made of the possibility of increasing the heat resistance of diane oligomers by means of the introduction of Cu2+, Co2+, or Ni2+ions into the polymer matrix. This was carried out by the hardening of epoxy oligomers with chelates of metals and aliphatic amines. The properties of polymers produced and their dependence on the quantity and structure of chelate hardener have been investigated. It has been established that maximal heat resistance is rendered by Cu2+, affording stability of DGEBA hardened to 280–300°C both in vacuum and in air. The heat resistance of copper-containing polymers has been shown to be higher than that of epoxy oligomers with known hardeners.