A life estimating apparatus estimating a residual life that is of a usable accumulated residual period of an energy storage device, the life estimating apparatus includes: a relational expression acquisition unit that acquires a relational expression, in which a resistance value of a DC resistance or an AC resistance of the energy storage device at an accumulated use period elapsed time point that is of an accumulated value of a use period of the energy storage device is given by an expression including a term of a function of the accumulated use period; and a residual life estimating unit that estimates the residual life of the energy storage device using the acquired relational expression. When a value in which the resistance value in the relational expression is differentiated by the accumulated use period twice becomes a positive value, the relational expression acquisition unit sets the accumulated use period to a relational expression acquisition period, and acquires the relational expression obtained from a relationship between the resistance value and the accumulated use period up to the relational expression acquisition period elapsed time point.