An electroendoscope apparatus which uses a plurality of types of electroendoscopes having solid-state imaging devices of different specifications and which performs signal processing on the basis of a plurality of signal processing systems, which includes: a video memory device used commonly among the plurality of signal processing systems; a circuit data recording device for recording circuit data corresponding to each of the plurality of signal processing systems; and a signal processing device, composed of programmable logic elements, which forms a dedicated processing circuit corresponding to each of the plurality of signal processing systems on the basis of the circuit data recorded by the circuit data recording device.