a test substrate;

an electrode specimen including a self-standing region and a region other than the self-standing region, the region other than the self-standing region having a metal current collector and an electrode mixture layer on at least one side of the metal current collector, and a surface of the electrode mixture layer being attached to the test substrate;

a fixing jig having a surface defining a recessed portion to hold an electrolyte solution in the recessed portion, the fixing jig being configured to fix the test substrate so that the region other than the self-standing portion of the electrode specimen attached to the test substrate is immersed in the electrolyte solution while the self-standing portion of the electrode specimen is not impregnated with the electrolyte solution; and

an adhesion strength measurement unit comprising a grip portion configured to grip the self-standing region of the electrode specimen and to apply a tensile force to the self-standing region in a direction perpendicular to the surface of the electrode mixture layer attached to the test substrate,

wherein the adhesion strength measurement unit is configured to measure an applied force at which the electrode mixture layer of the electrode specimen is peeled off of the test substrate by the tensile force.