One aspect relates to a container, in particular a bioreactor and/or mixing container, comprising: – an outer wall (101) designed to include a medium; and – a spectroscopy cell (1) arranged in and/or on the outer wall (101), wherein the spectroscopy cell (1) comprises: – a first optical area (10); – a second optical area (11) arranged opposite the first optical area (10), wherein the first optical area (10) and the second optical area (11) can be set at at least two different distances from one another; and – a specimen space (12) located between the first optical area (10) and the second optical area (11), wherein, at a measuring distance of the at least two different distances, the specimen space (12) can be filled with the medium and wherein, for the purposes of carrying out a spectroscopic measurement, at least one optical area has a light-transmissive embodiment. Further aspects relate to a spectroscopy cell and a spectroscopy method.
