To provide an apparatus and a method for producing micronized limestone powders to produce limestone micronized powders with a finer grain size from limestone improved in whiteness by way of a flotation process, by utilizing a wet crushing apparatus and a wet classifying apparatus.

This method for producing micronized limestone powders comprises: a step of floating and sorting limestone; a step of forming the limestone into a powder; a step of forming the powder into slurry in a slurry tank, and then into pulverized matter utilizing a crusher; and a step of classifying the pulverized matter into a fine powder and coarse powder utilizing a classifier. This apparatus for producing micronized limestone powders comprises: the slurry tank 130 for forming and storing the pulverized limestone in a slurry form; a pulverizer 140 for pulverizing the limestone slurry fed from the slurry tank linked thereto; and a wet classifying apparatus 170 for classifying the pulverized limestone pulverized in the pulverizer.