To provide a latch lock of a door which has an effect of preventing lockout, makes possible the easy combination of members, can miniaturize a lock box, is inexpensive, and can reduce the number of part items.

The latch lock of the door is provided with a latch, a latch operation lever, a handle cam, and a slider lock piece. The latch is always projected from the lock box, and the latch operation lever makes forward and backward movement together with the latch. The handle cam is incorporated into the lock box by an energizing means, and pulls back the latch based on the operation force of an operating handle of a door. The slider lock piece is engaged with the handle cam and locks the handle cam when it slides in the direction of an engagement pressing part formed at the latch operation lever by the operation a force of the indoor operation member. Even if the slider lock piece is brought into a state that it locks the handle cam at the time of opening of the door, the slider lock piece of the latch lock of the door is pushed back in the direction of lock release by the engagement pressing part when the latch moves backwardly due to sliding contact between the tip of the latch and the edge of a strike at the time of the closing of the door.