A device for processing the end yarn of a weft knitting machine capable of securely arresting and cutting crossed yarns produced in knitting a knitting fabric and properly processing end yarn after the cutting, wherein both a first gripper (11) and a second gripper (12) are movable in the longitudinal direction (16a) along the needle bed (16) of the weft knitting machine (15) and in an approaching/separating direction (16b) that approaches to and separates from the mouth portion (15a) of the needle bed (16a), switchable between a state of not holding a yarn (19) and a state of holding the yarn, and movable independently of each other. A cutter (13) cutting the yarn (19) is installed on the first gripper (11). A control means (14) controls the movements and the switching of the states of the first gripper (11), the second gripper (12), and the cutter (13) to cut the held yarn (19) with the cutter (13) with the yarn (19) held by the first gripper (11) and the second gripper (12). The end yarn produced by cutting the yarn (19) with the cutter (13) is not left in cut state, but processed by the first gripper (11) and the second gripper (12) independently of each other.