A foot bolt (10) of a sideways movable sliding door or a similar element (1-3), includes a part locking the element in the base, such as a pin fitting in the hole in the base. The foot bolt also has a counterpart (9) in the next element movable beside it, in which counterpart the part (13) in the edge of the preceding element can be fitted so that the adjacent elements get sideways interlocked. On moving the elements in the opposite direction, pushing of the last brought element away from the preceding element opens the locking of the preceding element from the base. The pin fitting in the hole in the base is intended to be manually pressed, for instance by the foot, into the hole.