To provide a continuous change-over ruler capable of picking out a necessary measure in multiple kinds of measure with a single ruler.

This ruler comprises a base 1, a turning bar 3, a winding bar 9 which is provided with a winding thumbscrew 9A (two winding bars 9 in front and in rear), a scale list A (covering the turning bar 3 and fixing each ends of the scale list A to the front and rear winding bars 9 for winding), and cover 5. The winding thumbscrew 9A is turned to wind the scale list A around the winding bar 9, so that a measure is sent out. By this, it functions as multiple rulers.