Disclosed is a luminescence measuring method which can produce a luminous intensity depending on the amount of a substance to be measured even when the substance occurs in a biological sample in an amount equal to or more than a given amount, and which can achieve quantitative measurement. The method is characterized by includes preparing a biological sample containing a luminescence-associated protein which is can react with a substance occurring in the biological sample in amount equal to or more than a given amount and which has a Km value equal to or higher than a predetermined value so that the luminous intensity can be quantified depending on the amount of the substance, measuring the luminescence intensity emitted from the biological sample, and outputting a result of the measurement on a regions and/or part of the biological sample.