Abstract: A separator abuts on a leading edge of a recording paper to separate it from a periphery of a paper roll when the paper roll is rotated forward in a paper feeding direction. The separator is attached to a supporting arm, which is urged by a spring so as to move the separator in accordance with a change of a diameter of the paper roll. The separator is provided with a vibration detecting sensor. While the paper roll is rotated backward in a winding direction, the vibration detecting sensor outputs a signal to a controller. This signal has a level corresponding to a scale of vibration. The controller detects the leading edge from the signal level when a head portion of the separator has overleapt the leading edge of the recording paper.