To provide a means for accurately detecting a slip between a paper band and a paper band carrier roller of a paper band feeder for feeding the paper band for binding bills.

This binding band feeder comprises: a first paper band monitoring sensor 46a arranged upstream in a feed direction A; a second paper band monitoring sensor 46b arranged downstream of the paper band carrier roller 31; a motor rotation amount measuring means for measuring the rotation amount of a paper band carrying motor 26; a torque limiter 27; a rotary encoder 47; and a driving roller rotation amount measuring means for measuring the rotation amount of a driving roller based on the output of the rotary encoder 47. The rotation amount of the motor during the passing of the paper band between the first and second paper band monitoring sensors 46a, 46b is measured by the motor rotation amount measuring means, and the rotation amount of the driving roller during that time is measured by the driving roller rotation amount measuring means. The slip between the paper band and the driving roller 32 is detected when the measured motor rotation amount exceeds a normal carrying determination value and when the difference between the motor rotation amount and the driving roller rotation amount is an error determination value or less.