Abstract: An apparatus for automatically analyzing genetic and protein materials using photodiodes. The apparatus comprises a computer for controlling the entire operation of the apparatus and analyzing a voltage level from a characteristic detector to analyze states of the genetic and protein materials, and an address decoder connected to the computer. The photodiodes are connected to the address decoder and generate currents in response to external light being incident thereon. A plurality of amplifiers are connected respectively to the photodiodes to amplify output currents therefrom, and a plurality of voltage output circuits are connected respectively to the amplifiers to convert output currents therefrom into voltages. An output selector selects any one of output voltages from the voltage output circuits under the control of the computer. The characteristic detector measures a level of an output voltage from the output selector and applies the measured voltage level to the computer.