There are provided a method of recovering a base paper for gypsum board for continuously and efficiently recovering a base paper for gypsum board from a waste material of gypsum board including a gypsum core and the base paper for gypsum board adhering thereto. The method of recovering a base paper for gypsum board includes steps of breaking the waste material of gypsum board, separating a gypsum component and a paper piece of the base paper for gypsum board from the broken waste material of gypsum board, and washing the separated paper piece with water using a rotary drum-type washing device so as to eliminate a gypsum component adhering to the paper piece.