The invention relates to a method for determining the current filling level of a liquid, preferably a calibrating, quality control, or cleaning fluid, or waste water, in a container, for example of an analyzer, where an immersion pipe is dipped into the liquid in the container to be filled or drained. The immersion pipe is connected to a pumping device via a tube system. The pressure p in the tube system is measured and increased, starting from the ambient pressure p₀, until a first discontinuous pressure change occurs at pressure p₁ due to the liquid column in the immersion pipe being forced out of the pipe, and/or the pressure p in the tube system is decreased until the liquid column in the immersion pipe reaches a change in cross-section of the immersion pipe, which change is situated above the maximum filling level of the liquid, such that a second discontinuous pressure change occurs at pressure p₂ due to the liquid column reaching the change in cross-section. The pressure difference between ambient pressure p₀ and the pressure p₁ or p₂ at one of the two pressure discontinuities or the time t₁ or t₂ until one of the two pressure discontinuities is reached, is recorded and used to determine the current filling level of the container.