To provide a roll paper residual quantity display device in which residual quantity of roll paper can be easily recognized.

A lever 2 in an L-shaped form is disposed to be rotatable around a shaft 6, and after a roll paper 1 is set, a first arm 4 of the lever 2 is necessarily actuated downward by weight of the lever 2, so it necessarily gets in contact with an outer circumference of the roll paper 1. In a housing cover 7, a part where a second arm 8 points is a window 8 using transparent material, etc., so pointing of the second arm 3 of the lever 2 can be structurally recognized on the outer side of the housing cover 7. A direction which the second arm 3 points is a display 9 in the case where residual quantity of the roll paper 1 is large, that is where an outer diameter of the roll paper 1 is large, as in the case of a new roll, and it points a display 9a in the case where the residual quantity of the roll paper 1 becomes less, that is where the outer diameter of the roll paper 1 becomes smaller.