The present invention provides an apparatus for correcting a voltage of a secondary battery, wherein accuracy in measurement of battery voltages between battery blocks in different voltage measurement systems. In a battery ECU (101), the following components are disposed: a first voltage measuring part (102-1), a second voltage measuring part (102-2), a third voltage measuring part (102-3) and a fourth voltage measuring part (102-4) which are disposed in different voltage measurement systems so as to measure voltages of plural battery blocks; a representative voltage calculating part (105) for calculating representative voltages from battery voltages measured by the first to fourth voltage measuring parts; a voltage correction value calculating part (107) for calculating voltage correction values on the basis of the respective representative voltages; and a correction value reflecting part (109) for adding the voltage correction values to measured voltages of battery blocks in the respective corresponding voltage measurement systems.