An image pickup apparatus includes a plurality of pixels arranged in rows and columns, a plurality of comparators, each of the comparators including a switch for controlling an operation, a signal line which is provided commonly to the switches of the plurality of comparators and through which a control signal for controlling the switches of the plurality of comparators is supplied, a control signal generation unit, and a signal line control unit configured to control an electric potential of the signal line to be set as a fixed electric potential.