PURPOSE: To obtain an information recorder which can detect that the both sides of a roll-shaped recording sheet are inversely set, and allow an operator to know it by outputting a test print at the time of setting the recording sheet.

CONSTITUTION: When the recording sheet is ejected by a sheet ejecting roller 10, and an ejection sensor 12 is turned off, a test print output is started. That is, the rotation of a platen roller 5 is started in a positive direction, a recording sheet 1 is carried, and the prescribed test print is outputted by a recording head 6. When the recording part of the test print passes the ejection sensor 12, the ejection sensor 12 detects whether or not the test print is recorded on the recording sheet 1. When the recording of the test print is not confirmed by the ejection sensor 12, that is, when the recording sheet is inversely set, an error message 'the recording sheet is inversely set' is displayed at the display on the upper face of this device, and an alarm is issued to the operator.