The present invention relates to a water level sensor, and an object thereof is to provide a military self-propelled artillery, etc. moderate to improve the starting performance of the cold weather and hokseogi the equipment cooling water level sensor, according to embodiments of the invention for this purpose, engine internal at the cooling water level sensor comprising a sensing rod operating point it is formed to determine whether or not the cooling water, which is connected to the sensing and the sensing rod detects the output capacity of the cooling unit; Delay timer unit for setting a delay time according to the capacity of the cooling water detected by the sensing unit; And when it reaches the delay time set by the delay timer, the control unit for outputting a signal, and by including a technical base. In contrast to this, according to the invention according, moderate to improve the starting performance of the cold weather and hokseogi of equipment, and there is an effect that it is possible to mount the water level sensor in the cooling water of the gas warning device adapted vehicles have a temperature of the engine.