Provided is a centrifugal separator having a simple configuration, with which the concentration of solid components in waste excreted from a separation chamber of a centrifugal separator can be stabilized at a high concentration, the amount of waste excreted can be reduced, and storage space for the waste can be reduced. A separating-plate-type centrifugal separator is provided with a system controller 17 having a memory 17A for storing initial turbidities divided into multiple groups and an excretion trigger table created from multiple increments NTU corresponding to respective groups of the initial turbidities, and a central computing-and-processing device 17B which determines an excretion reference value for excreting solid components S in a separation chamber 15 on the basis of the initial turbidities of the excretion trigger table and the increments NTU corresponding to the initial turbidities.