To obtain a fold type knife which has a knife blade almost flush with a U-shaped grip.

This fold type tool is provided with a U-shaped grip 1, a knife 4 to be housed into the grip at the closed position, a tongue 5 which is disposed at one end of the knife 4 and mounted pivotally movable centering round a pivot shaft 6 extending in the direction of the flatness of the knife 4 between two support legs 2 and 3 of the grip 1 and a lock leg 10 extending parallel with the support legs 2 and 3. The lock leg 10 is elastically supported inside the first support leg 2 so that the free end part thereof is pressed toward the first support leg 2 against the action of a spring force. A slit 13 that can be engaged with an engaging part of the tongue 5 is formed to lock the knife 4 at the position of being opened by 180°. The locking of the knife can be released by pressing the tip of the lock leg 10 toward the first support leg 2.