Disclosed is a battery cell voltage measuring apparatus and method. The battery cell voltage measuring apparatus comprises a plurality of floating capacitors provided corresponding to a plurality of cells contained in a battery pack; a plurality of switching units provided corresponding to each cell of the battery pack and switchable into a charge mode or a measurement mode; and a cell voltage detector for measuring the voltage of each cell by switching each switching unit into a charge mode to charge the voltage of each cell on each corresponding floating capacitor and time-differentially switching each switching unit into a measurement mode to apply the cell voltage charged on the floating capacitor between a reference potential and a common cell voltage measuring line.