A sheet conveying device includes a conveyor for conveying a sheet along a predetermined conveyance path and a feeder unit for supporting the sheet to be fed to the conveyor. The conveyor includes a first guide part for guiding the sheet toward a downstream side in the conveying direction in a direction inclined at a downward gradient, a second guide part for guiding the sheet from the first guide part toward a further downstream side in a direction inclined at an upward gradient, a suction roller arranged at the first guide part for conveying the sheet supported by the feeder unit toward the downstream side, and a first conveyance roller arranged at the second guide part and for conveying the sheet conveyed by the suction roller toward the downstream side one at a time.