An elevator system provided in an existing apartment building, includes a motor that is a drive source for a lifting mechanism of an elevator car, a power storage device configured to store power supplied to the motor, and a charger configured to charge the power storage device with power supplied from a power grid. A traveling motor, an in-vehicle power storage device, and an in-vehicle charger of a used vehicle are diverted to the motor, the power storage device and the charger. The power storage device is used as a normal power supply of the elevator system. The motor is driven by power supplied from not the power grid but the power storage device.