Provided is a power distribution box distributing commercial electric power supplied from lead-in electric power lines into branch electric power sources and supplying the branch electric power sources to respective loads connected thereto. More particularly, the present invention relates to a power distribution box equipped with a resistive leakage current detector extracting a resistive leakage current simply and accurately from a resultant leakage current and causing leakage current interruption and alarm to be actuated according to the extraction result. The power distribution box equipped with the resistive leakage current detector of the present invention includes: a zero-phase current transformer detecting a resultant leakage current; a voltage detector detecting voltage of branch lines; a power calculator calculating wasted power; a phase difference calculator calculating a phase difference; and a resistive leakage current extractor extracting a resistive leakage current, wherein the power calculator calculates apparent and effective power.