Long-term exposure of a polycrystalline fullerene C_60 film in a constant electric field of 1–4 MV/cm produces an electroforming effect manifested by increase in conductivity of the film within several orders of magnitude. After this electroforming, the current–voltage ( I – U ) characteristic shows a high degree of current stability and reproducibility of results. In fields of 10^5–10^6 V/cm, the I – U characteristics of electroformed films are determined by the space-charge limited current. The concentration ( N _ t ≈ 4 × 10^21 m^–3) of carrier traps and their energy ( E _ t ≈ 0.176 eV) have been estimated.