To provide the manufacturing method and device of artificial sand that is not a dangerous substance as a recyclable resource while reasonably and safely treating a waste base and a waste acid at a low cost.

The device comprises a neutralizing granulation tank 3 into which each of the proper amount of a powdered basic waste and a liquid acid waste is charged after the each is suitably taken out, a neutralizing granulation device 4 for kneading and stirring these charged substances while neutralizing and granulating them, a cyclone 5 for sucking the gas generated in connection with the chemical reaction in the tank 3 and for feeding the gas to a process where the gas is appropriately processed, a gas cleaning device 6 for processing the fed gas, a vaporizing/separating device 7 for heating the granulated substance after granulated and discharged from the device 4 to vaporize unnecessary components for separation and for increasing the chemical stability of the substance after cooled, and a product storage tank 8 for storing the sandy substance where the purity of the salt of the granulated substance manufactured in the device 7 is enhanced.