A yarn processing apparatus comprising: a yarn processing unit configured to perform a predetermined process for yarns running in a yarn running direction while being aligned in an arrangement direction intersecting with the yarn running direction; a first regulatory guide which includes first grooves aligned in the arrangement direction and which is provided upstream of the yarn processing unit in the yarn running direction; a second regulatory guide which includes second grooves provided at the same intervals as the first grooves in the arrangement direction and which is provided downstream of the yarn processing unit in the yarn running direction; a first yarn holding component which includes first retaining grooves provided at the same intervals as the first grooves in the arrangement direction and which is able to hold the yarns that are to be threaded to the first regulatory guide; and a second yarn holding component which includes second retaining grooves provided at the same intervals as the second grooves in the arrangement direction and which is able to hold the yarns that are to be threaded to the second regulatory guide, the first yarn holding component being movable between a yarn threading position where the yarns are threaded to the first retaining grooves and a handover completion position where the handover of the yarns to the first regulatory guide is completed, the second yarn holding component being movable between a yarn threading position where the yarns are threaded to the second retaining grooves and a handover completion position where the handover of the yarns to the second regulatory guide is completed, the first yarn holding component at the yarn threading position being adjacent to the second yarn holding component at the yarn threading position in the yarn running direction, and when viewed in the arrangement direction, an angle (x) between (i) a first depth direction that is a direction toward the bottom of each of the first retaining grooves of the first yarn holding component at the yarn threading position and (ii) a second depth direction that is a direction toward the bottom of each of the second retaining grooves of the second yarn holding component at the yarn threading position being an acute angle. a first regulatory guide which includes first grooves aligned in the arrangement direction and which is provided upstream of the yarn processing unit in the yarn running direction; a second regulatory guide which includes second grooves provided at the same intervals as the first grooves in the arrangement direction and which is provided downstream of the yarn processing unit in the yarn running direction; a first yarn holding component which includes first retaining grooves provided at the same intervals as the first grooves in the arrangement direction and which is able to hold the yarns that are to be threaded to the first regulatory guide; and a second yarn holding component which includes second retaining grooves provided at the same intervals as the second grooves in the arrangement direction and which is able to hold the yarns that are to be threaded to the second regulatory guide, the first yarn holding component being movable between a yarn threading position where the yarns are threaded to the first retaining grooves and a handover completion position where the handover of the yarns to the first regulatory guide is completed, the second yarn holding component being movable between a yarn threading position where the yarns are threaded to the second retaining grooves and a handover completion position where the handover of the yarns to the second regulatory guide is completed, the first yarn holding component at the yarn threading position being adjacent to the second yarn holding component at the yarn threading position in the yarn running direction, and when viewed in the arrangement direction, an angle (x) between (i) a first depth direction that is a direction toward the bottom of each of the first retaining grooves of the first yarn holding component at the yarn threading position and (ii) a second depth direction that is a direction toward the bottom of each of the second retaining grooves of the second yarn holding component at the yarn threading position being an acute angle.