A printing media supply device for use in an image forming apparatus includes a printing media supply cassette adapted to receive a stack of printing media. A pick-up roller picks up the printing media stacked in the printing media supply cassette. The pick-up roller has a pick-up member for picking up the printing media, and a rotation member for supporting the pick-up member. The rotation member has a buffer surface formed by cutting a portion of a leading edge portion thereof away. The buffer surface may be formed so as to expose side surfaces of the pick-up member. The pick-up roller applies a substantially uniform pressure to the printing media even when there is a large quantity of printing media stacked in the printing media supply cassette, and thereby minimizes multifeeding of the printing media. Accordingly, the supply of printing media is stable, improving the printing media supply efficiency.