To make a liner lock type folding knife usable with excellent safety by providing a handle on the opposite side to a lock liner plate of the knife with an unlocking button.

The liner lock type folding knife is designed to place the finger on the line of rotation of a blade at the time of folding and is, therefore, extremely dangerous. The folding knife is, thereupon, provided with a button at the handle on the opposite side of the lock liner plate and is so constituted as to be unlocked by the button. The safe use of the knife is made possible and the degree of freedom on the position of the unlocking button may be increased according to the constitution to provide the knife with the button on the opposite side to the lock liner plate.