To easily change a position in a height direction of a latch bolt to a handle cam or a lock cam.

In a lock, a latch bolt 6 is energized by a latch spring 3 and housed in a box-shaped case and the latch bolt 6 is moved back by an arm part 7a of a handle cam 7 turned by an operation member to perform unlocking. In the lock, a latch 6a of the latch bolt 6 is guided by a guide hole 9a of a guide member 9, a position in a vertical direction of the guide hole 9a is changeable by the arrangement of the guide member 9, the arm part 7a is engaged with a back end of the latch bolt 6 regardless of the position in the vertical direction of the guide hole 9a, and a back end of the latch spring 3 is supported by a spring bearing seat 2 movable in the vertical direction further.