PURPOSE: To provide a liquid surface measuring device, whereby an absolute value of molten metal surface level is grasped and rise of the surface at initiation of work is measured, and that is not affected by external turbulance such as splash and responds well.

CONSTITUTION: A high frequency pulse voltage oscillator 2, a probe array 3 and a receiver 4 are provided, and the prove array 3 is assigned, in parallel with fluctuation direction of molten metal surface level L in a mold 5, in coolent 8 of a cooling device 7 provided at a mold outer wall part 6, a liquid surface measuring device 1 thus configured.