To provide a winding unit having a configuration in which a yarn feeding bobbin is replaced while suppressing a rise in manufacturing cost and lowering in quality of a package.

A winder unit includes: a bobbin holding part; a bobbin supply device; a winding part; a yarn splicing device; a chase part detection sensor; and a determination part. The bobbin holding part holds a yarn feeding bobbin. The bobbin supply device performs a supplying operation of the yarn feeding bobbin to the bobbin holding part. The winding part performs a winding operation of winding a yarn of the yarn feeding bobbin held by the bobbin holding part to form a package. The yarn splicing device performs a yarn splicing operation of splicing a yarn end of the package and a yarn end of the yarn feeding bobbin when the yarn is cut. The chase part detection sensor detects presence/absence of the yarn feeding bobbin at the bobbin holding part. The determination part determines whether supply of the yarn feeding bobbin is successful based on a detection result of the chase part detection sensor after the bobbin supply device performs the supplying operation of the yarn feeding bobbin and until the yarn splicing device starts the yarn splicing operation.