A solid-state imaging element comprising: a test signal supply unit configured to supply, as a test signal, a signal that fluctuates with time; a plurality of photoelectric conversion elements to each of which a pixel address is allocated and wherein each photoelectric conversion element is configured to convert incident light into a current signal by photoelectric conversion; a plurality of address event detection circuits to each of which a pixel address is allocated, wherein each address event detection circuit is connected to a photoelectric conversion element having the same pixel address, and wherein each address event detection circuit comprises: a current-voltage conversion circuit configured to convert the current signal into a voltage signal; a buffer configured to output a buffer input signal as a buffer output signal; a subtractor configured to receive the buffer output signal or a second test signal included in the test signal provided by the test signal supply unit and to output, as a differential signal, a change amount of a signal differentiated by subtraction, a selection unit (361, 362, 363) configured to select either a signal output by the subtractor or the test signal; a comparator configured to compare a predetermined threshold value with the signal selected by the selection unit (361, 362, 363), and output a result of the comparison, and a transistor (364, 365) configured to open and close, in accordance with a predetermined enable signal, a path between a power source and the current-voltage conversion circuit, the buffer, the subtractor, and the comparator. a test signal supply unit configured to supply, as a test signal, a signal that fluctuates with time; a plurality of photoelectric conversion elements to each of which a pixel address is allocated and wherein each photoelectric conversion element is configured to convert incident light into a current signal by photoelectric conversion; a plurality of address event detection circuits to each of which a pixel address is allocated, wherein each address event detection circuit is connected to a photoelectric conversion element having the same pixel address, and wherein each address event detection circuit comprises: a current-voltage conversion circuit configured to convert the current signal into a voltage signal; a buffer configured to output a buffer input signal as a buffer output signal; a subtractor configured to receive the buffer output signal or a second test signal included in the test signal provided by the test signal supply unit and to output, as a differential signal, a change amount of a signal differentiated by subtraction, a selection unit (361, 362, 363) configured to select either a signal output by the subtractor or the test signal; a comparator configured to compare a predetermined threshold value with the signal selected by the selection unit (361, 362, 363), and output a result of the comparison, and a transistor (364, 365) configured to open and close, in accordance with a predetermined enable signal, a path between a power source and the current-voltage conversion circuit, the buffer, the subtractor, and the comparator. a current-voltage conversion circuit configured to convert the current signal into a voltage signal; a buffer configured to output a buffer input signal as a buffer output signal; a subtractor configured to receive the buffer output signal or a second test signal included in the test signal provided by the test signal supply unit and to output, as a differential signal, a change amount of a signal differentiated by subtraction, a selection unit (361, 362, 363) configured to select either a signal output by the subtractor or the test signal; a comparator configured to compare a predetermined threshold value with the signal selected by the selection unit (361, 362, 363), and output a result of the comparison, and a transistor (364, 365) configured to open and close, in accordance with a predetermined enable signal, a path between a power source and the current-voltage conversion circuit, the buffer, the subtractor, and the comparator.