Provided is a concentration measurement device 1A, comprising: a probe 20 which is attached to a head part, said probe 20 further comprising a light source 21 which outputs measurement light, and a photodetector part 22 which generates a detection signal based on the intensity of incident light a computation unit 12 which, on the basis of the detection signal which is based on the intensity of the measurement light which has propagated within the head part, computes a numerical value which is associated with hemoglobin concentrations of the head part which fluctuate due to repeated chest compression and an instruction unit 13 which instructs the computation unit 12 to commence the computing. The photodetector unit 22 generates the detection signal continuously from before the commencement of the computation of the computation unit 12. The instruction unit 13 determines the commencement of the computation on the basis of the detection signal. A concentration measurement device and concentration measurement method are thus achieved whereby it is possible to automatically determine an appropriate timing for a commencement of a measurement.本發明之濃度測定裝置1A具備:探針20,其具有輸出測定光之光源21、及產生與入射光之強度相應之檢測信號之光檢測部22,且安裝於頭部;運算部12,其基於與在頭部之內部傳輸之測定光之強度相應之檢測信號,而計算因胸外按壓之反覆進行而變動的與頭部之血紅素濃度相關之數值;及指示部13,其指示運算部12開始計算。光檢測部22自運算部12之計算開始前便持續地產生檢測信號。指示部13基於該檢測信號而決定計算之開始。藉此,實現能夠自動地判斷測定開始之恰當時點之濃度測定裝置及濃度測定方法。1A‧‧‧濃度測定裝置10‧‧‧本體部11‧‧‧控制部12‧‧‧運算部13‧‧‧指示部14‧‧‧偵測部15‧‧‧顯示部16‧‧‧監視部17‧‧‧揚聲器20‧‧‧探針21‧‧‧光源22‧‧‧光檢測部22a‧‧‧第1光檢測器22b‧‧‧第2光檢測器25‧‧‧保持部30a‧‧‧連接器30b‧‧‧連接器31‧‧‧電纜32‧‧‧電纜X1‧‧‧第1距離X2‧‧‧第2距離
