An optical connector connecting a plurality of optical fiber lines and a plurality of optical devices, the optical connector comprising: an optical fiber line fixing block comprising a plurality of insertion grooves in which end portions of the plurality of optical fiber lines are inserted; the optical connector further comprising a submount comprising a single flat surface on which the optical fiber line fixing block and the plurality of optical devices are disposed together, the submount comprising first guide-walls determining a position of the optical fiber line fixing block and second guide-walls determining a position of the plurality of optical devices, the optical fiber line fixing block and the plurality of optical devices being automatically aligned by the first guide walls and the second guide walls, the first guide-walls and the second guide-walls protruding upwardly from the single flat surface from positions that are distinct from each other, the first guide-walls being disposed on both sides of the optical fiber line fixing block and the first guide-walls surrounding corners of the optical fiber line fixing block, and the second guide-walls being disposed on both sides of the plurality of optical devices, the optical fiber line fixing block including a block substrate and a base supporting the plurality of optical fiber lines on the block substrate, the plurality of insertion grooves being multiple gaps formed between a plurality of third guide-walls on the base, the optical connector further comprising a reflection plate disposed on end portions of the plurality of optical fiber lines, and supports disposed on upper portions of the plurality of optical devices so as to support the reflection plate, and the reflection plate comprising a groove formed in a portion placed on the end portions of the plurality of optical fiber lines, the groove of the reflection plate being shaped like a recess having a wider upper side than a lower side thereof, the plurality of optical devices being provided as an array, and the plurality of optical devices being light-receiving devices or light-emitting devices, the plurality of insertion grooves, the first guide-walls, and the second guide-walls being disposed at predetermined positions so that the end portion of the plurality of optical fiber lines and the plurality of optical devices are disposed in line, the reflection plate having an angle with respect to the upper surfaces of the plurality of optical devices, wherein the angle of the reflection plate is adjusted according to positions of the supports for varying the lengths of the optical paths between the plurality of optical devices and the plurality of optical fiber lines. an optical fiber line fixing block comprising a plurality of insertion grooves in which end portions of the plurality of optical fiber lines are inserted; the optical connector further comprising a submount comprising a single flat surface on which the optical fiber line fixing block and the plurality of optical devices are disposed together, the submount comprising first guide-walls determining a position of the optical fiber line fixing block and second guide-walls determining a position of the plurality of optical devices, the optical fiber line fixing block and the plurality of optical devices being automatically aligned by the first guide walls and the second guide walls, the first guide-walls and the second guide-walls protruding upwardly from the single flat surface from positions that are distinct from each other, the first guide-walls being disposed on both sides of the optical fiber line fixing block and the first guide-walls surrounding corners of the optical fiber line fixing block, and the second guide-walls being disposed on both sides of the plurality of optical devices, the optical fiber line fixing block including a block substrate and a base supporting the plurality of optical fiber lines on the block substrate, the plurality of insertion grooves being multiple gaps formed between a plurality of third guide-walls on the base, the optical connector further comprising a reflection plate disposed on end portions of the plurality of optical fiber lines, and supports disposed on upper portions of the plurality of optical devices so as to support the reflection plate, and the reflection plate comprising a groove formed in a portion placed on the end portions of the plurality of optical fiber lines, the groove of the reflection plate being shaped like a recess having a wider upper side than a lower side thereof, the plurality of optical devices being provided as an array, and the plurality of optical devices being light-receiving devices or light-emitting devices, the plurality of insertion grooves, the first guide-walls, and the second guide-walls being disposed at predetermined positions so that the end portion of the plurality of optical fiber lines and the plurality of optical devices are disposed in line, the reflection plate having an angle with respect to the upper surfaces of the plurality of optical devices, wherein the angle of the reflection plate is adjusted according to positions of the supports for varying the lengths of the optical paths between the plurality of optical devices and the plurality of optical fiber lines.