The invention relates to a method for monitoring the temperature of a cryopreserved biological sample. The invention also relates to a device for monitoring the temperature of a cryopreserved biological sample. The device (10) for monitoring the temperature of a cryopreserved biological sample comprises a sample container (1) having a receiving space (2) for receiving a biological sample (6). The device also comprises at least one chamber (11) having an interior that is not fluidically connected to the receiving space (2) and is only partially filled with an indicator substance (7) with a melting temperature in a region of −20° C. to −140° C. The chamber (11) has a barrier (13) that causes the indicator substance (7) to move into a second sub-region (12b) of the chamber (11) when the indicator substance (7) in a first sub-region (12a) of the chamber is in the fluid aggregate state.