To allow an operator to adequately judge whether or not a front or rear face of a thermal recording paper is correctly set by looking at the thermal recording paper, and to prevent the thermal recording paper from being unnecessarily consumed.

This recorder comprises a main thermal head 1 for printing received information on a thermal recording paper and an auxiliary thermal head 6 for test printing that executes printing operation for indicating that the front face of the thermal recording paper is reversed with respect to the adequate orientation in an initial paper feeding process which is executed for adjusting a top position of the set thermal recording paper 10. The auxiliary thermal head 6 is disposed on a position at a front side of the position of the main thermal head 1 in the paper feeding direction and at the opposite side of the thermal head 1 with a paper path L.