A blood glucose measurement system in which a blood glucose level measured with an invasive blood glucose measurement apparatus 101 is used to calibrate a blood glucose level measured with a non-invasive blood glucose measurement apparatus 102, comprising a controller that outputs an invasive actuation signal that starts the detection of a characteristic quantity in the body with the invasive blood glucose measurement apparatus, and a blood sampling component for collecting blood from the body on the basis of the invasive actuation signal, wherein measurement with the invasive blood glucose measurement apparatus is begun when the amount of change in the estimated blood glucose level has reached or exceeded a non-invasive blood glucose threshold.