Provided is a solid-state imaging apparatus including: imaging pixels each configured to generate an imaging signal through photoelectric conversion; focus detection pixels each configured to generate a focusing signal through photoelectric conversion; and an adding unit configured to add the imaging signals generated by the imaging pixels to generate an added imaging signal, and configured to add the focusing signals generated by the focus detection pixels to generate an added focusing signal, in which a number of the focusing signals to be used by the adding unit to generate one added focusing signal is larger than a number of the imaging signals to be used by the adding unit to generate one added imaging signal, and operation for outputting the added focusing signal and operation for outputting each of the focusing signals without adding are selectively carried out.