A sleep state management device includes a sensor that detects movement in bedding where a measurement subject is sleeping, and a control unit that calculates a peak value difference, which is a difference between adjacent peak values in a detection signal outputted from the sensor, determines that a period in which a number of times the peak value difference exceeds a threshold is greater than a predetermined value is a period in which the measurement subject has moved, and manages the sleep state of the measurement based on a result of the determination.