To provide a method for producing a wet master batch capable of widely improving its cleaning effect in preparing the wet master batch continuously by mixing slurry solution containing a filler with rubber solution and a coagulating agent containing an acid to coagulate, separating a solid portion from coagulation liquid containing the coagulated materials, then cleaning for removing the coagulating agent attached on or contained in the solid portion in the process of the coagulation, dehydrating and drying, a wet master batch formed by the same method, a rubber composition and a tire.

This method for producing the wet master batch is provided by in dehydrating the solid portion 18, performing the cleaning while dehydrating by using a centrifugal dehydrating machine 1 having a rotating filter disc 2, and also spraying cleaning liquid 17 on the solid portion in parallel to the centrifugally dehydrating the solid portion 18.