Abstract: A microfilm search device for distinguishing presence of frames from a change in quantity of transmitted light between the opposed optical fiber end faces between which a microfilm is placed. A pair of opposed blocks for holding optical fibers are arranged across the microfilm in a width direction with placing the microfilm therebetween. Light is guided into the optical fibers held by one block from a light source, passes through the microfilm, and enters the optical fibers held by other block. A quantity of entered light is detected by photosensor and an output thereof is binarized. Based on binarized signals, the presence of frames is determined. End portions of optical fibers on the side of the light source are bunched, and a bunched portion is detachably and non-rotatably held relative to one lamp. Frame detection condition due to light quantity can be uniform and maintained easy after disassembly, inspection, maintenance of the device.