To provide a manufacturing method and a manufacturing apparatus of a granular tile material by which the granular tile material, that has no sharp edge at its surface and thereby is excellent in safety, can be manufactured from tiles such as a waste tile and further to provide culture soil and a water quality improving material which are consisting of the granular tile material manufactured by the manufacturing method or the manufacturing apparatus of the granular tile material and which are excellent in safety, water retention, water permeability, filterability and appearance.

The manufacturing method comprises a crushing process for crushing the tile to a granular shape and a grinding process for forming the granular tile material having no edge at its surface by grinding the surface of the granular tile with an inner peripheral surface of a trough 20 and a surface of a screw 22 by transporting the granular tile crushed at the crushing process to an oblique upward direction with a screw conveyor C which is constituted by providing the screw 22 capable of rotationally driving in the trough 20 disposed so that a shaft line is inclined.