An apparatus for controlling step charging of a secondary battery, comprising: a voltage measuring unit, a current measuring unit and a temperature measuring unit configured to measure a voltage, a current and a temperature of the secondary battery, respectively; and a charging control unit operably coupled to the voltage measuring unit, the current measuring unit and the temperature measuring unit, wherein the charging control unit is configured to execute a process including: a control logic for estimating a state of charge and an open circuit voltage of the secondary battery based on the measured voltage value, the measured current value and the measured temperature value before the start of charging of the secondary battery; a control logic for determining a polarization voltage of the secondary battery from at least an internal resistance of the secondary battery, the measured current value and the estimated OCV; a control logic for determining an OCV deviation corresponding to a difference between the estimated OCV and a predefined minimum OCV value; a control logic for determining a correction factor corresponding to the determined polarization voltage and the determined OCV deviation with reference to a predefined correlation between the polarization voltage and the correction factor and between the OCV deviation and the correction factor; a control logic for determining a look-up SOC by correcting the estimated SOC according to the correction factor; a control logic for determining the magnitude of a charging current corresponding to the look-up SOC and the measured temperature value with reference to a predefined correlation between the SOC and the charging current and between the temperature and the charging current; and a control logic for providing the determined charging current to a charging device so that a charging current corresponding to the determined magnitude of the charging current is applied to the secondary battery. a voltage measuring unit, a current measuring unit and a temperature measuring unit configured to measure a voltage, a current and a temperature of the secondary battery, respectively; and a charging control unit operably coupled to the voltage measuring unit, the current measuring unit and the temperature measuring unit, wherein the charging control unit is configured to execute a process including: a control logic for estimating a state of charge and an open circuit voltage of the secondary battery based on the measured voltage value, the measured current value and the measured temperature value before the start of charging of the secondary battery; a control logic for determining a polarization voltage of the secondary battery from at least an internal resistance of the secondary battery, the measured current value and the estimated OCV; a control logic for determining an OCV deviation corresponding to a difference between the estimated OCV and a predefined minimum OCV value; a control logic for determining a correction factor corresponding to the determined polarization voltage and the determined OCV deviation with reference to a predefined correlation between the polarization voltage and the correction factor and between the OCV deviation and the correction factor; a control logic for determining a look-up SOC by correcting the estimated SOC according to the correction factor; a control logic for determining the magnitude of a charging current corresponding to the look-up SOC and the measured temperature value with reference to a predefined correlation between the SOC and the charging current and between the temperature and the charging current; and a control logic for providing the determined charging current to a charging device so that a charging current corresponding to the determined magnitude of the charging current is applied to the secondary battery. a control logic for estimating a state of charge and an open circuit voltage of the secondary battery based on the measured voltage value, the measured current value and the measured temperature value before the start of charging of the secondary battery; a control logic for determining a polarization voltage of the secondary battery from at least an internal resistance of the secondary battery, the measured current value and the estimated OCV; a control logic for determining an OCV deviation corresponding to a difference between the estimated OCV and a predefined minimum OCV value; a control logic for determining a correction factor corresponding to the determined polarization voltage and the determined OCV deviation with reference to a predefined correlation between the polarization voltage and the correction factor and between the OCV deviation and the correction factor; a control logic for determining a look-up SOC by correcting the estimated SOC according to the correction factor; a control logic for determining the magnitude of a charging current corresponding to the look-up SOC and the measured temperature value with reference to a predefined correlation between the SOC and the charging current and between the temperature and the charging current; and a control logic for providing the determined charging current to a charging device so that a charging current corresponding to the determined magnitude of the charging current is applied to the secondary battery.