A method for controlling a device for detecting nucleic acid amplification, the device comprising: a loading unit (4, 37) being capable of loading a plurality of reaction containers for nucleic acid amplification, each reaction container containing a sample and a reagent, and having a thermoregulation unit capable of thermoregulation for nucleic acid amplification; and a measurement unit being disposed facing the loading unit, and measuring a reaction in the loaded reaction containers; the method comprising: making a repeat of a rotational movement or linear movement of the measurement unit in a predetermined direction relative to the loading unit to sequentially receive a measurement signal from each of the samples in the reaction containers loaded in the loading unit at timings in fixed periods, characterised in that each of the loading unit and the measurement unit has an independent movement mechanism (12, 15), and thereby, when loading of a new reaction container is requested during measurement of a previously loaded reaction container, the velocity of the measurement unit relative to the loading unit is controlled with the independent movement mechanism such that the measurement unit maintains the relative velocity in response to movement of the loading unit while an empty position on the loading unit is moved to a reaction-container loading gate (16, 34), and the measurement unit moves at a fixed velocity as the relative velocity while the loading unit stops and a new reaction container is loaded into the loading unit without interrupting the measurement of a previously loaded reaction container. a loading unit (4, 37) being capable of loading a plurality of reaction containers for nucleic acid amplification, each reaction container containing a sample and a reagent, and having a thermoregulation unit capable of thermoregulation for nucleic acid amplification; and a measurement unit being disposed facing the loading unit, and measuring a reaction in the loaded reaction containers; the method comprising: making a repeat of a rotational movement or linear movement of the measurement unit in a predetermined direction relative to the loading unit to sequentially receive a measurement signal from each of the samples in the reaction containers loaded in the loading unit at timings in fixed periods, characterised in that each of the loading unit and the measurement unit has an independent movement mechanism (12, 15), and thereby, when loading of a new reaction container is requested during measurement of a previously loaded reaction container, the velocity of the measurement unit relative to the loading unit is controlled with the independent movement mechanism such that the measurement unit maintains the relative velocity in response to movement of the loading unit while an empty position on the loading unit is moved to a reaction-container loading gate (16, 34), and the measurement unit moves at a fixed velocity as the relative velocity while the loading unit stops and a new reaction container is loaded into the loading unit without interrupting the measurement of a previously loaded reaction container. making a repeat of a rotational movement or linear movement of the measurement unit in a predetermined direction relative to the loading unit to sequentially receive a measurement signal from each of the samples in the reaction containers loaded in the loading unit at timings in fixed periods, characterised in that each of the loading unit and the measurement unit has an independent movement mechanism (12, 15), and thereby, when loading of a new reaction container is requested during measurement of a previously loaded reaction container, the velocity of the measurement unit relative to the loading unit is controlled with the independent movement mechanism such that the measurement unit maintains the relative velocity in response to movement of the loading unit while an empty position on the loading unit is moved to a reaction-container loading gate (16, 34), and the measurement unit moves at a fixed velocity as the relative velocity while the loading unit stops and a new reaction container is loaded into the loading unit without interrupting the measurement of a previously loaded reaction container.