PURPOSE: To achieve a simple structure and sure operation in a lock mechanism for a moving body such as a drawer used in furniture or the like, by making a lock member equipped with guide pins connected to a pair of guide channels formed on a pair of side walls, and a projection which can freely contact a connecting means of the moving body.

CONSTITUTION: A lock mechanism A restricts the movement toward the side of a curved channel part 13b, by connecting a projecting part 22 on this side of a lock member 20 to a projection-like connecting means M' installed on a moving body M at the movement ending position on the push-in side of the moving body M. Under this condition, if the moving body M is moved to this side, that is, the side of the curved channel part 13b against a spring 30, the lock member 20 is also moved to the side of the curved channel 13b. When a guide pin on this side among guide pins 40, 40 connected to the inside of a straight channel part 13a, reaches the curved channel part 13b, the lock member 20 is inclined downward along the curve, and consequently, the connection between the projecting part 22 on this side of the lock member 20 and the connecting means M', is released.