First and second measurement probes come into contact with first and second electrode pads, respectively, and third and fourth measurement probes come into contact with the first and second electrode pads, respectively. A current flows in a current path including the first and second electrode pads and a plurality of lines through the first and second measurement probes. A value of the current in the current path is measured, and a value of a voltage between the third and fourth measurement probes is measured. Conductivity between the first and second electrode pads is inspected based on the measured value of the current and the measured value of the voltage.