An oscillating loop taker includes a bobbin case holder having a needle thread guiding projection which with a wedge forms a recess in which fits a driver member. A radial dimension from an axis of rotation of the holder to an inner leading edge portion of the projection is less than a radial dimension from such axis to an inner surface of the holder defining a space within which is housed a projection. The inclination of a needle thread guide face at the recess side of the projection is set to a desired comparatively large value. The circumferential length of the needle thread guide face is made comparatively long to enable a needle thread to be easily transferred onto the outer circumferential face of the bobbin case. Thereby, the bobbin thread is permitted to pass between the inner peripheral face in the vicinity of the base end portion of the projection and the outer peripheral end portion of the bobbin case. This enables the bobbin case in the bobbin case holder to be enlarged, enabling the diameter of a bobbin accommodated in the bobbin case holder also, to be enlarged, and enabling the winding capacity of the bobbin thread wound on the bobbin to be increased.