PURPOSE:To prevent bugs moving on a recording sheet transport path from entering into a transfer device by ensuring that a high voltage power supply part is electrically connected to an insecticidal mesh part 4 at a time than when a control circuit part is activated to print data. CONSTITUTION:A high voltage output from a high voltage power supply part 9 is divided using a voltage dividing resistor 11 and the divided voltage is applied to an insecticidal mesh part 12. The applied voltage is a voltage which can generate an electric discharge between an insecticidal mesh high voltage part 12a and an insecticidal mesh gland part 12b but to such an extent that the voltage is high enough to kill bugs. If bugs entering from a recording sheet cassette 1 or a recording sheet discharge aperture 10 come in contact with the insecticidal mesh high voltage part 12a and the insecticidal mesh gland part 12b simultaneously when they move in a narrow transport path and passes through the insecticidal mesh part 12, the bugs become electrocuted or thrown into a syncopic state due to a high voltage applied to the insecticidal mesh part 12. Subsequently, the bugs are prevented from finding their way into a transfer device 6.
