PURPOSE: To enable the use of both of general-purpose recording paper and OHP paper and to realize high quality sharp recording, by providing at least two kinds of heat generators different in heating temp. and heating a recording medium corresponding to the property of the recording medium.

CONSTITUTION: Each of heat generators 11a, 11b is a positive characteristic thermistor for a heater having temp. self-control action and, as the heat generator 11a, one with Curie temp. of about 140°C is used and, as the heat generator 11b, one with Curie temp. of about 80°C is used. The heat generators 11a, 11b different in heating temp. are respectively connected in parallel and changed over by a switch 13. The switch 13 is operated by a user corresponding to the property of the recording medium 9 and changed over so as to be connected to the heat generator 11a when the recording medium 9 is general-purpose recording paper such as generally available paper of fine quality and switched over for connection to the heat generator 11b when the recording medium 9 is OHP paper.