A device 4 to measure a degree of acquisition is provided to present objective scientific data of an educational effect by applying brain science to an educational field. A device 4 to measure a degree of acquisition comprises a measuring portion 1 that measures a blood amount or/and a blood component amount in a predetermined measuring region S of brains of a subject P, a diachronic change data producing portion 2 that obtains the blood amount or/and the blood component amount measured in the above-mentioned measuring portion 1 chronologically and produces diachronic change data as data showing diachronic change of the blood amount or/and the blood component amount, and a waveform output portion 3 that outputs a waveform of the diachronic change data in each work in a comparable manner in case the subject P repeatedly conducts the predetermined work several times.