PURPOSE: To enable the correction of operation by the self-security of horizontality in the installation on an arbitrary surface, by providing a device consisting of two electric contacts opening and closing by vibration to a liquid sealed container and connecting the lead wires led out from the electric contacts to an external terminal.

CONSTITUTION: The liquid 19 received in a container 18 has high viscosity and high specific gravity and is poor in flowability and a light wt. mercury seisoscope is fixed at the surface of the liquid in a state floated in parallel to the surface of the liquid. If this container 1g is vibrated, the seismoscope is also similarly vibrated and mercury 9 is shifted to open or close the contact between a metal container 7 and a hermetic terminal 8. As mentioned above, because the horizontality of the seismoscope floated on the surface of the liquid 19 can be secured by allowing the surface of the liquid 19 to hold horizontality, it becomes unnecessary to adjust the same.