The present invention relates to an apparatus for continuous-direct-resistance heating of long-length articles wherein the travelling long-length article is made to contact with roll electrodes disposed in a specified spacing, then made to pass through an annular transformer disposed between the roll electrodes.Conductive members with sufficiently less electrical resistance than that of the long-length article located between the both electrodes are disposed on the periphery of the transformer with the both ends thereof connected to the roll electrode through a slider, thereby a current being induced in the long-length article with the conductive member as the retrace, which heats the long-length article having a higher resistance very efficiently, neither resulting in an external voltage, nor causing electrically any obstacle to the production line in which the apparatus is installed.The apparatus comprises three roll electrodes, two transformers and conductive members being disposed on the periphery of the transformer connected to the neighboring roll electrode, the power being fed to each transformer from two single-phase transformers in the Scott connection with a three-phase power supply, thus providing heating without developing imbalance in the three-phase voltage.