To enable a sheet to be easily set at a specified position according to the size of the sheet in spite of a small sheet size difference by improving the visibility.

A sheet feeding device 100, which is equipped with locking groove groups 142, 143 corresponding to the sheet sizes of printing mediums to store the printing mediums, includes a size indicator 144 attached onto a printing medium mounting face to indicate the size of printing medium and a pair of right and left guide members 110, 120 for guiding the printing medium in such a manner allowing the printing medium to slide in a direction orthogonal to a printing medium feeding direction, wherein the left guide member 110 is provided with locking members to be locked to the locking groove groups 142, 143 and both of the size indicator 144 and the locking groove groups 142, 143 are formed in two arrays respectively.