To provide a guide device of a printing apparatus which makes printing of enlarged characters and a plurality of lines easy, accurate and quick.

A guide member 41 of a guide device 40 has an opening 43 longitudinal in a print direction and a feed roller 47 which can move the guide member 41 in a feed direction orthogonal to the print direction. A main body case 2 of a printing apparatus 1 is inserted in the opening 43 of the guide member 41 and moved in the print direction along the opening 43. As a result, characters or images are printed linearly to a recording paper 15 by a recording head set at a lower end part of the main body case 2. When the guide member 41 is moved in the feed direction with a predetermined feed pitch to repeat the printing operation by the printing apparatus 1 again, enlarged characters can be printed accurately.