The present invention provides an evaluation method for evaluating whether
a light-emitting element material to be evaluated is suitable for a host
material or a guest material. By carrying out a first step of measuring
absorption intensity of a light-emitting element material and a second
step of irradiating the light-emitting element material with light for a
predetermined period of time, repeatedly; thereby a change in absorption
intensity with time is evaluated so that whether the light-emitting
material is suitable for a host material or a guest material can be
distinguished. The light emitted to the light-emitting element material
preferably has a wavelength component which is absorbed by a skeleton
which contributes to excitation of the light-emitting element material.