Abstract: The invention relates to a method and arrangement for removing gas from a fibre/liquid suspension in a fibre treatment line in a pulp mill, which line includes at least one stage in which the fibre/liquid suspension is treated and/or stored in a large container (2) before being conveyed for further treatment. The fibre/liquid suspension is conveyed to the large container via a vessel (15) which with its lower part communicates with the large container and has a significantly smaller horizontal sectional area than the large container, but extends upwards above the level (4) of the fibre/liquid suspension in the large container, with gas being removed from the fibre/liquid suspension (19) in the area (18) of the upper part of the smaller vessel by means of the area being subjected to a subatmospheric pressure.