PROBLEM TO BE SOLVED: To provide a highly convenient measuring device, measuring system, measuring method, and electronic apparatus including the measuring device.SOLUTION: A measuring device 10 for measuring a concentration of a prescribed component in a blood of a test object coming into contact with a measuring section 21, includes: an irradiation part 12 for applying light to a suspected area of the test object； a light receiving section 13 for receiving reflected light from the suspected area； a pressure detection section 11 for detecting a pressure in the measuring section 21； and a calculation section 20 that calculates the concentration of the component on the basis of an output of the light receiving section 13 when the pressure is within a first range and an output of the light receiving section 13 when the pressure is within a second range.【課題】利便性の高い測定装置、測定システム、測定方法、及び測定装置を備える電子機器を提供する。【解決手段】測定部２１に接触する被検体の血液中の所定の成分の濃度を測定する測定装置１０は、被検体の被検部位に光を照射する照射部１２と、被検部位からの反射光を受光する受光部１３と、測定部２１における圧力を検出する圧力検出部１１と、圧力が第１の範囲のときの受光部１３の出力と、圧力が第２の範囲のときの受光部１３の出力とに基づいて、成分の濃度を算出する算出部２０とを備える。【選択図】図１
