A method for measuring the presence or absence and/or strength of the inhibitory activity of a test substance on binding between a ligand and a receptor thereof, which comprises the following steps (1) to (3):(1) immobilizing either of the test substance or the ligand on a solid support;(2) contacting the test substance and the ligand for a given period of time in the presence or absence of the receptor for the ligand; and(3) comparing the level of binding between the test substance and the ligand in the presence and absence of the receptor.