The invention provides a sheet conveying device, an image forming apparatus, and image reading apparatus, differing from a method for increasing separation nip pressure but increasing holding force from a friction pad to paper to prevent excessive friction between the friction pad and the paper, convert ringing into mute, and prevent multiple paper refeeding and not feeding. In sheet conveying device using a friction separation manner, a pair of guides (50A) are disposed on the outer sides of the two ends of the axis direction of the sheet conveying roller (47) at the upstream side of the conveying direction of a separation nip area (N2) in order to pick up papar P to face the bottom of a friction pad (48) side. Viewed from the axis direction of the axis direction of the sheet conveying roller (47), the tops (50A1) of the guides (50A) is separated from the separation nip area (N2) and is superposed on the outer peripheral surface of the sheet conveying roller (47).