To determine the quality of an insulating state of a to-be-measured electric line even if a voltage is not measured at the to-be-measured electric line.

A leakage current measurement apparatus comprises: a current detecting section 2 provided with a current sensor 2a clamped to the electric lines 11, 12, and detecting a leakage current Io flowing in the electric lines 11, 12; a voltage detecting section 3 for detecting an AC voltage V1 at the electric lines 11, 12; and a processing section 4 for calculating an effective leakage current Ior based on the AC voltage V1 detected by the voltage detecting section 3 and the leakage current Io detected by the current detecting section 2. When the AC voltage V1 is less than a reference voltage Vr, the processing section 4 causes a display section 6 to display the leakage current Io detected by the current detecting section 2 without calculating the effective leakage current Ior. When the AC voltage V1 is the reference voltage Vr or more, the processing section 4 calculates the effective leakage current Ior, and causes the display section 6 to display the effective leakage current Ior along with the leakage current Io.