Abstract: An inverse-time relay is disclosed which comprises a voltage dividing circuit for dividing a d.c. voltage proportional to a current value in a line to be protected by a plurality of ratios different from one another thereby to provide a plurality of voltage values, a voltage saturating circuit for saturating each of the divided voltage values at a predetermined value, and a microcomputer for achieving an inverse-time operation employing the plurality of voltage values obtained from the voltage dividing circuit. The microcomputer makes comparison between each of the plurality of the voltage values obtained from the voltage dividing circuit and the saturation voltage as to whether or not the former is smaller than the latter, and, for the divided voltage smaller in magnitude than the saturation voltage, counts the operating time corresponding to that voltage and delivers a decision output when the count has reached the operating time.