An automatic analysis apparatus, comprising: a light source for transmitting light along an optical axis towards a substance to be measured; a receptor element for detecting a transmitted light quantity distribution for a plurality of wavelengths when measuring transmitted light which has passed through the substance to be measured from the light source; a data storage unit for storing a current transmitted light quantity distribution for the plurality of wavelengths detected by the receptor element and for preliminarily storing known transmitted light quantity distributions for the plurality of wavelengths, the distributions showing properties of the reduction of transmitted light quantity against the plurality of wavelengths due to deterioration, and a control unit for comparing the known transmitted light quantity distributions preliminarily stored in the data storage unit with the current transmitted light quantity distribution acquired at the time of measurement characterized in that the known transmitted light quantity distributions include, for each of at least two component parts of the automatic analysis apparatus, an initial transmitted light quantity distribution for the plurality of wavelengths and an experimentally determined transmitted light quantity distribution (403, 404) for the plurality of wavelengths when the component part has deteriorated, and further include a transmitted light quantity distribution measured immediately after installing the automatic analysis apparatus in a place where it is to be used, wherein the at least two component parts include the light source and one or more component parts disposed on the optical axis; wherein the control unit is adapted to calculate a correlation from the current transmitted light quantity distribution and the known transmitted light quantity distributions using a wave-shape correlation operator and, based on the result of the correlation calculation, to calculate a degree of deterioration of each of the at least two component parts. a light source for transmitting light along an optical axis towards a substance to be measured; a receptor element for detecting a transmitted light quantity distribution for a plurality of wavelengths when measuring transmitted light which has passed through the substance to be measured from the light source; a data storage unit for storing a current transmitted light quantity distribution for the plurality of wavelengths detected by the receptor element and for preliminarily storing known transmitted light quantity distributions for the plurality of wavelengths, the distributions showing properties of the reduction of transmitted light quantity against the plurality of wavelengths due to deterioration, and a control unit for comparing the known transmitted light quantity distributions preliminarily stored in the data storage unit with the current transmitted light quantity distribution acquired at the time of measurement characterized in that the known transmitted light quantity distributions include, for each of at least two component parts of the automatic analysis apparatus, an initial transmitted light quantity distribution for the plurality of wavelengths and an experimentally determined transmitted light quantity distribution (403, 404) for the plurality of wavelengths when the component part has deteriorated, and further include a transmitted light quantity distribution measured immediately after installing the automatic analysis apparatus in a place where it is to be used, wherein the at least two component parts include the light source and one or more component parts disposed on the optical axis; wherein the control unit is adapted to calculate a correlation from the current transmitted light quantity distribution and the known transmitted light quantity distributions using a wave-shape correlation operator and, based on the result of the correlation calculation, to calculate a degree of deterioration of each of the at least two component parts.