A solid-state imaging apparatus includes a plurality of pixels arrayed in a matrix, and configured to generate signals by photoelectric conversion; a plurality of read-out circuits disposed on each column of the plurality of pixels arrayed in a matrix pattern, and configured to read out the signals from the plurality of pixels; a plurality of comparison units configured to compare the signals output from the plurality of read-out circuits with a reference signal whose level changes with time; a counter configured to count a clock signal after the level of the reference signal starts a change; a storage unit configured, when a magnitude relationship between the signals output from the plurality of the read-out circuits and the reference signal is reversed; and a reset unit configured to reset the count value stored in the storage unit.