A semiconductor wafer baking apparatus includes a hot plate, a container of which an upper part is open, and a cover that covers the upper part of the container. The cover includes an upper plate, a lower plate and a side wall that form a gas circulating space therebetween. At least one gas inlet is formed in the side wall, a plurality of gas supply holes are formed in a central region of the lower plate, and a skirt on which is formed a gas exhaust unit is coupled to a lower edge of the cover.