A sheet conveying device, that can be included in an image forming apparatus, includes a first conveying unit to convey a sheet in a first sheet conveying direction, a second conveying unit including a sheet holding section to hold and transfer the sheet in a second sheet conveying direction, a sheet conveying path provided between the first conveying unit and the second conveying unit, a belt-type sheet conveying unit including a belt and first and second rotary belt holding members, a shaft holding member to hold the first and second rotary belt holding members to be spaced at a given constant interval, and a regulation member to regulate a movement of the belt in the sheet width direction.