A small and low-cost capacity equalizing apparatus for equalizing the capacities of battery blocks constituting an assembled battery, each battery block comprising one or multiple secondary batteries and the battery blocks being connected in series.The capacity equalizing apparatus in accordance with the present invention comprises an assembled battery, n discharge devices and a controller. The assembled battery has a configuration wherein n battery blocks (n is a positive integer of 2 or more), each comprising one or multiple secondary batteries, are connected in series. The n discharge devices, each connected across the positive and negative electrode terminals of each of the n battery blocks, discharge the secondary batteries inside the respective battery blocks. The controller has a first control section to which the battery blocks are electrically connected and a second control section electrically insulated from the first control section. The controller individually controls at least two of the discharge devices.