Abstract: The atmospheric pressure actuated alarm of the present invention comprises a pressure transducer which senses the atmospheric pressure and produces an electrical transducer signal in response thereto. A difference amplifier is connected to the pressure transducer for measuring the transducer signal and for producing an output signal whenever the transducer signal is of a magnitude outside a predetermined range. An operational amplifier is connected to the difference amplifier for amplifying the transducer signal. A latch is connected to the operational amplifier for receiving the amplified signal. A signal alarm and a power source are connected in series with the latch. The latch is changeable from an open condition to a closed condition in response to the amplified signal being greater than a predetermined magnitude. When the latch moves to the closed condition, it connects the power source to the alarm signal and causes actuation of the alarm signal.