There is provided a cutter for a double-edged eyelid-forming tape or thread. After the tape or thread has been attached to an eyelid, the cutter can perform a cutting action on an extra portion of the tape or thread. A cut is formed in a metal plate to extend from its front end to an intermediate position. By bending a pair of cut pieces in opposite directions, a cutting part is formed on the first end side of a cutter piece. A holding part on the second end side of the cutter piece is embedded in a gripping piece and is secured. Each cut piece is formed with a curved surface on the first end side from the terminating part of the cut through a bent front end to a bent width end. The cut piece is extended from the bent width end to a front end edge.