A detection apparatus includes a substrate which includes a plurality of pixels arranged in a matrix and adapted to generate pixel signals, a plurality of drive lines arranged in a column direction and each connected in common to a plurality of pixels in a row direction, a plurality of data lines arranged in the row direction and each connected in common to a plurality of pixels in the column direction, connection terminals smaller in number than the data lines, and a multiplexer unit provided between the connection terminals and the data lines; a read circuit provided with a reset switch for supplying a constant potential to the connection terminals and connected to the connection terminals; a drive circuit adapted to control driving of the plurality of pixels; and a control circuit adapted to supply a control signal to the substrate and the read circuit.