Cash box with automatic verification

A box of money, with a reception area (12) for receiving documents of value, a unit of nonuse (14) for irreversible disablement of valuable documents arranged in the reception area (12), a sensor unit (18) with at least one sensor (20) for detecting tampering attempts, and a control unit (16) for controlling the drive of nonuse (14), the control unit (16) being structured such that in an oN state operation box money, it triggers the action of the unit of nonuse, when the sensor unit (18) detects a manipulation attempt, and in a state of oFF operation of the cassette of money, it does not trigger the action of disablement unit (14) in the event of an attempt at tampering, characterized in that the control unit (16) is structured such that, before activation of the cassette diner or she check function as intended of at least one sensor (20) of the sensor unit (18), and that the control unit (16) has been allocated a nominal signal value for each of the sensors (20) which must be checked before activation, and that the control unit (16) is structured such that for checking the function of each of the sensors (20) to be checked , it may determine an actual value of the respective sensor signal (20), and compare this actual value signal is determined with the respective nominal signal value.