A glass substrate chemical strengthening furnace apparatus includes a bottom portion and a side wall extending from an edge of the bottom portion, where the bottom portion and the side wall define a reaction space; and a plurality of heaters providing heat to the reaction space. The bottom portion includes an inclined portion located at a center and a collection portion disposed between the inclined portion and the side wall, the collection portion is in a groove shape in which an upper surface thereof is further recessed than the inclined portion, and the plurality of heaters includes a bottom heater disposed in the bottom portion or adjacent to the bottom portion.