This estimation device for estimating the quantity of electricity remaining in a storage cell or battery pack executes: first processing for estimating the quantity of electricity remaining, on the basis of an integrated value of the current of a storage cell or a battery pack; second processing for estimating a cumulative error in the quantity of electricity remaining, on the basis of an integrated value of the measurement error for the current; third processing for estimating the quantity of electricity remaining by a different method than with the first processing; fourth processing for calculating a remaining electricity quantity difference, which is the difference between the quantity of electricity remaining estimated in the first processing and the quantity of electricity remaining estimated in the third processing; and fifth processing for calculating a correction value for the measurement error, on the basis of the cumulative error and the remaining electricity quantity difference.