Disclosed is a method for measuring an immunostimulatory response of an immune cell, including (i) bringing a measurement target immune cell into contact with an immunostimulator, (ii) forming a contact surface with a substance different from the measurement target immune cell on the measurement target immune cell, (iii) bringing the measurement target immune cell into contact with a capturing body that binds to a surface antigen on the contact surface and is capable of generating an optical signal, (iv) detecting the optical signal generated from the capturing body, and (v) determining whether or not the measurement target immune cell from which the contact surface has been eliminated before detecting the optical signal has an immunostimulatory response, based on the detected optical signal.