A surface-plasmon enhanced fluorescence measurement method in which fluorescence (β) that is emitted from a fluorescent substance for labeling a detection-target substance when the fluorescent substance is excited by localized light based on surface plasmon resonance is detected to detect the presence or amount of the detection-target substance, the method comprising: installing an analysis chip in a chip holder fixed to a conveyance stage having a conveyance direction, the analysis chip including: a prism having an incidence surface, an emission surface, and a film-formation surface; a metal film disposed on the film-formation surface and including a capturing region having a surface to which a capturing body for capturing the detection-target substance is fixed; and a positioning mark which is formed on a plane identical to that of the metal film and in which a scattered state of plasmon scattering light (γ) emitted from the mark is different from a scattered state of plasmon scattering light (γ) emitted from a region around the mark, and wherein the mark is outside of the capturing region and is disposed in the conveyance direction with respect to the capturing region; irradiating and scanning a rear surface of the metal film corresponding to the mark in the analysis chip installed in the chip holder with excitation light (α) through the incidence surface, detecting plasmon scattering light (γ) emitted from the vicinity of the mark, identifying the position of the mark from variation in the detected plasmon scattering light and identifying the center of the capturing region from a distance between the center portion of the mark and the position of the center portion of the capturing region to identify a degree of shifting in position of the capturing region from a measurement position; moving the chip holder by the degree of shifting by the conveyance stage in the conveyance direction to move the capturing region to the measurement position; and irradiating a rear surface of the metal film corresponding to the capturing region disposed at the measurement position with excitation light and detecting fluorescence emitted from the fluorescent substance labeling the detection-target substance captured by the capturing body. installing an analysis chip in a chip holder fixed to a conveyance stage having a conveyance direction, the analysis chip including: a prism having an incidence surface, an emission surface, and a film-formation surface; a metal film disposed on the film-formation surface and including a capturing region having a surface to which a capturing body for capturing the detection-target substance is fixed; and a positioning mark which is formed on a plane identical to that of the metal film and in which a scattered state of plasmon scattering light (γ) emitted from the mark is different from a scattered state of plasmon scattering light (γ) emitted from a region around the mark, and wherein the mark is outside of the capturing region and is disposed in the conveyance direction with respect to the capturing region; a prism having an incidence surface, an emission surface, and a film-formation surface; a metal film disposed on the film-formation surface and including a capturing region having a surface to which a capturing body for capturing the detection-target substance is fixed; and a positioning mark which is formed on a plane identical to that of the metal film and in which a scattered state of plasmon scattering light (γ) emitted from the mark is different from a scattered state of plasmon scattering light (γ) emitted from a region around the mark, and wherein the mark is outside of the capturing region and is disposed in the conveyance direction with respect to the capturing region; irradiating and scanning a rear surface of the metal film corresponding to the mark in the analysis chip installed in the chip holder with excitation light (α) through the incidence surface, detecting plasmon scattering light (γ) emitted from the vicinity of the mark, identifying the position of the mark from variation in the detected plasmon scattering light and identifying the center of the capturing region from a distance between the center portion of the mark and the position of the center portion of the capturing region to identify a degree of shifting in position of the capturing region from a measurement position; moving the chip holder by the degree of shifting by the conveyance stage in the conveyance direction to move the capturing region to the measurement position; and irradiating a rear surface of the metal film corresponding to the capturing region disposed at the measurement position with excitation light and detecting fluorescence emitted from the fluorescent substance labeling the detection-target substance captured by the capturing body.