An image reading device and an image forming apparatus having the same, that can prevent unnecessary wear of components or damage of a document when a simplex scanning operation is carried out. The image reading device includes a first reading unit and a second reading unit. The first reading unit includes a first scan unit to scan a first surface of a document, a first press member mounted while opposing the first scan unit, and a first elastic member to bias the first scan unit or the first press member to closely contact the document with the first scan unit. The second reading unit includes a second scan unit to scan a second surface of the document, a second press member mounted while opposing the second scan unit, and a second elastic member to bias the second scan unit or the second press member to closely contact the document with the second scan unit. The second scan unit and the second press member are separated from each other by a lifting device. The first elastic member to bias the first scan unit or the first press member has an elastic force different from an elastic force of the second elastic member to bias the second scan unit or the second press member.