To provide a lock mechanism of a cabinet for office supplies, having double-swinging doors with grips, which is set up such that by locking a lock device provided for one of the doors, a lock device provided for the other door is activated, to thereby achieve simultaneous locking of both the doors.

The double-swinging doors consisting of the first door A and the second door B, are provided with the lock devices with operating levers, respectively. A first locking portion 4 provided for the first door A has a locking rod that is activated upon locking operation by a key to disable a lock canceling function of the operating lever, and has a pressing portion 47 protruding from an edge of the first door A upon operation of the locking rod, in the vicinity of the edge of the first door. A second locking portion 8 provided for the second door B has a locking rod that has a pressure receiving portion 87 opposed to the pressing portion 47, located in the vicinity of an edge of the second door, and disables a lock cancellation function of the operating lever of the second lock device when the pressure receiving portion 87 is squeezed from the edge of the door.