There is provided a technique for avoiding test-time IR drops which occur when the frequency that adjacent FFs in a scan chain have different logical values increases. An expected value derivation module derives the expected value of each FF by calculating probability propagation or performing logic simulation. A grouping module groups each FF subject to a test into a number of groups by referring to the obtained expected value. A scan chain configuration module pairs two groups whose logical-value-1 intake frequencies are opposite to each other, performs logic reversal on one group, and configures one scan chain.