A junction-current probe is provided which can measure a current flowing in a junction port adapted to connect a circuit board or an electronic apparatus to a chassis under the condition that the circuit board or electronic apparatus is packaged to the chassis. Structurally, the current probe has a circular or rectangular insulator having a hole in the center, a coiled conductor wire for converting linkage flux into voltage, an insulating member for preventing the insulator from making electrical contact with surroundings, an extraction lead for connecting opposite ends of the conductor wire to a cable and the cable for connection to a measurement unit. The current probe is reduced in thickness within in a range in which the condition of packaging to the chassis can remain unchanged.