Abstract: Disclosed is a liquid level detection apparatus using the Archimedean principle suited for the measurement of the level of a liquid, in particular a high temperature molten metal. The liquid level detection apparatus is comprised of a probe (3) which inserted in a molten metal (2) and receives a buoyancy corresponding to the level of the liquid, an arm (4) which is supports the probe at one end, a support (7) which supports the arm, a force detector (8) which is provided under the other end of the arm and detects the buoyancy received by the probe through the arm, and a signal processing means (13) which performs operational processing on the electrical output signals of the force detector and finds the level corresponding to the output.