The present invention provides a blood glucose meter in which a good balance between measurement accuracy and low power consumption can be achieved by performing measurement with a frequency of sampling clock that ensures sufficient accuracy as well as with minimum time.A clock for acquiring digital data from an A/D converter is determined based on a required resolution and a slope of a blood glucose measurement curve. Clock generators are configured so that the sampling clock is suitably set according to operating modes of the blood glucose meter. Particularly, the clock generators are configured so that high-speed clock pulses are continuously generated in a mode that determines measurement start, and, from the time when spotting is detected, measurement operation of a timer and the like is started, and the mode is switched from continuously generating the clock pulse to intermittently generating the clock pulses.
