It is an object of the present invention to provide a measurement method
which can suppress noise when a specific binding reaction between a
physiologically active substance and a test substance is measured using a
surface plasmon resonance measurement device. The present invention
provides a method for measuring a change in surface plasmon resonance
which comprises: using a surface plasmon resonance measurement device
comprising a metal film, a light source for generating a light beam, an
optical system for allowing the above-described light beam to enter the
interface of the metal film so that total reflection conditions can be
obtained at the interface thereof and so that various incidence angles
can be included, a flow channel system comprising a cell formed on the
above-described metal film, and a light-detecting means for detecting the
state of surface plasmon resonance by measuring the intensity of the
light beam totally reflected at the above interface, and exchanging the
liquid contained in the above flow channel system with another liquid,
wherein the liquid in the above-described flow channel system is
exchanged with another liquid obtained by eliminating insoluble matters
from a measurement solvent, and the change in surface plasmon resonance
is then measured in a state where the flow of the liquid has been
stopped.