1. An automated analyzer comprising: a reaction container; first dispense means for dispensing a sample of an examination item to the reaction container; second dispense means for dispensing a reagent to be reacted with the sample dispensed to the reaction container; a stirrer for mixing the sample and the reagent in the reaction container; a photometer configured to detect one or more measurements of a reaction process of the sample and the reagent in the reaction container; a storage that stores a determination formula and a distribution of approximation formula parameters and shape feature quantities obtained in advance for a normal state and a plurality of approximation formulas in association with at least one of reagent information or examination item information, the approximation formulas including Expression (4) to Expression (7) as follows: 
 x=a*t+b+c *exp(− k*t )  (4) 
 x=a*t+b+e /( t+d )  (5) 
 x=a*t+b+w /{exp( u*t )+ v} (6) 
 x=a*t+b+p *log {1+ q *exp( r*t )}  (7); wherein t denotes time, x denotes absorbance, and each of a, b, c, d, e, k, p, q, r, u, v, and w are parameters; and a control unit configured to: acquire, from the photometer, a plurality of measurement point data of the reaction process select, based on a combination of the reagent and the examination item, one of the plurality of approximation formulas stored in the storage to approximate the plurality of measurement point data; store the plurality of measurement point data to obtain a threshold number of measurement point data; determine the parameters of the selected approximation formula for minimizing a difference between a time change of an absorbance expressed by the selected approximation formula and a time change of an actual absorbance; determine, based on the selected approximation formula, an approximated curve that approximates the plurality of measurement point data; determine at least one shape feature quantity (1) to (4) from the approximated curve as an index, wherein a tangent of the approximated curve at a start of the reaction process is a first straight line, and a straight line that approaches the approximated curve is a second straight line, the shape feature quantities (1) to (4) including: (1) a time when the first and second straight lines intersect, (2) a time when the second straight line approaches below a predetermined threshold, (3) a difference between values of the first and second straight lines at a reaction start time, (4) a difference between slopes of the first and second straight lines; determine an abnormal measurement based at least on the index obtained from the approximated curve and at least one of: the determination formula defined in advance for a type of abnormality based on prior normal and abnormal data; or the distribution of approximation formula parameters and shape feature quantities obtained in advance for a normal state; and in response to determining the abnormal measurement, output a result including an indication of the abnormal measurement.