There is provided an interconnection substrate used in skew adjustment between output pins in a test apparatus, the test apparatus supplying a test signal to a device under test to test the device under test, the interconnection substrate including: a first terminal coupled to a first output pin that outputs the test signal; a second terminal coupled to a second output pin that outputs the test signal; a first interconnection connecting the first terminal to a bonding node; a second interconnection connecting the second terminal to the bonding node; and a third interconnection connecting the bonding node to an output node, where the first interconnection and the second interconnection have a length equal to each other.