Provided are a measuring device and a measuring method that use terahertz light, by which a substance to be detected can be detected with high sensitivity and high accuracy. A measuring device using a pulsed electromagnetic wave is provided with a substance detection plate, a means for generating the pulsed electromagnetic wave having amplitude intensity dependent on the amount of a substance to be detected at an irradiation position by irradiating the substance detection plate with a pulsed laser beam, and a detection means for detecting the amplitude intensity of the pulsed electromagnetic wave, and measures the change of the state of a solution containing the substance to be detected on the basis of the amplitude intensity.
