An image reading device includes an image reading section, a document table, a document pressing member, and a document size indication section. The image reading section reads an image of a document. The document table is located above the image reading section. The document is loaded on the document table. The document pressing member is provided over the document table in an openable and closable manner to press the document. The document size indication section is located on the document table and indicates a plurality of document sizes. The document size indication section is constituted by a semitransparent resin plate and includes a letter presenting portion. A part of the semitransparent resin plate of the document size indication section corresponding to the letter presenting portion has a smaller thickness than a part of the document size indication section other than the part thereof corresponding to the letter presenting portion.