PURPOSE: To raise the safety of door lock by using double locking as well as make the confirmation of locking easier by a method in which a latch hub is separated into parts for inner and outer handles, and a latch hub stopper is set to restrain the outer handle when a dead bolt is projected.

CONSTITUTION: A latch hub 23 is separated into parts for inner and outer handles, and retractors 20 for each are allowed to operate independently. A latch hub stopper 24 is provided and connected to the latch hub 23b for outer handle when a dead bolt 1 is projected to restrain the outer handle. When the outer handle is operated, locking state, if any, can be confirmed immediately. A releasing lever 27 to interlock to the retractor 20 interlocking with the inner handle is provided to enable the operating lever 4 of the head bolt 1 to restore, and even when the bolt 1 is projected, unlocking can be permitted only by operation of the inner handle.