An imaging apparatus includes a plurality of unit pixels arranged in a matrix and configured to generate a signal by photoelectric conversion, a plurality of pixel output lines connected to each column of the unit pixels, a plurality of column amplifiers configured to amplify a signal of the pixel output lines, and a driving circuit configured to generate a control signal of the column amplifiers. Each of the column amplifiers includes first and second input terminals, an output terminal, an input capacitance between the first and second input terminals, and a first switch between the second input and output terminals. The driving circuit is configured to generate the control signal so as to make a period for switching the first switch from a conductive state to a non-conductive state longer than a period for switching the first switch from the non-conductive state to the conductive state.