PURPOSE: To make it possible to respectively deal with the accurate measurement of the turbidity of a turbid liquid different in turbidity, by a method wherein at least three light receiving parts are provided and the respective distances of the light receiving parts from a light source are made different to each other.

CONSTITUTION: A turbidity meter is constituted so that a light source 10 and light receiving parts 16 are arranged to the surface 6' of a substrate 4 provided in a state immersed in a turbid liquid so that the light emitted from the turbid liquid reaches the light receiving parts 16. In this case, at least three light receiving parts 16 are mounted and the respective distances of the light receiving parts 16 from the light source 10 are made different. By this constitution, it is enabled to respectively deal with the accurate measurement of the turbidity of the turbid liquid different in turbidity.