An analysis method for detecting an amount of a substance by irradiating an analysis chip containing the substance and detecting a quantity of light output from the analysis chip. The analysis method including irradiating an incident surface of the analysis chip and another surface adjacent to the incident surface with detection light while changing a relative position of the detection light with respect to the analysis chip, detecting reflected light from the incident surface of the analysis chip, and acquiring information on a position of the analysis chip from a relationship between a quantity of the reflected light detected and the relative position. The analysis method determines if the analysis chip is abnormal when a quantity of target reflected light is equal to or lower than a predetermined light quantity.