Cutter knife

A cutter knife comprising a case having an inner space extending in a forward and rearward direction and a slit continuing to the inner space, the slit being formed in the forward and rearward direction on an upper end portion in the case, a cutter blade housed in the case and provided such that the cutter blade may appear from a forward end of the case, a slider holding the cutter blade and provided movably in the forward and rearward direction in the case, and a plate spring attached to the slider and provided engageably and disengageably on the case side to permit locking and unlocking the slider, the slider including a slider body located in the case, and an actuating member combined relatively movably in the forward and rearward direction relative to the slider body and located on the upper portion side of the case through the slit,

• wherein an initial position keeping mechanism of the actuating member is provided between the slider body and the actuating member, the initial position keeping mechanism including a position-restricting portion provided in the plate spring, and a receiving portion provided in the actuating member and receiving the position-restricting portion;
• and
• the actuating member is kept in an initial position relative to the slider body, while the position-restricting portion is received by the receiving portion, and on the other hand the relative movement between the slider body and the actuating member is permitted by displacing the position-restricting portion within the receiving portion.