To prevent a recording sheet from contacting a recording head by adjusting a gap between a platen glass and a sheet pressing member corresponding to a thickness of the recording sheet.

When a recording sheet S to be supplied is conveyed on a platen glass 8 by means of a conveying roller 4a and a pinch roller 4b, a thickness of the recording sheet S is detected by a thickness detecting sensor 7. A position of a sheet pressing member 6 with respect to the platen glass is adjusted in accordance with the detected result and the recording sheet is adequately pressed so that catching of the recording sheet by the sheet pressing member or contamination of the recording sheet due to contacting of the recording sheet with a recording head is prevented.