A sheet feeding device has a sheet stacking tray, a sheet stop portion, a sheet feed roller, a separation member, a first urging member, an eccentric cam, a cam follower, a sheet detection mechanism, and a holding mechanism. The holding mechanism holds the separation member at a position away from the sheet feed roller after a half-moon-shaped feed surface has passed across the separation member as the sheet feed roller rotates. Immediately before a sheet starts to be fed, the sheet stacking tray is kept on standby at a standby position radially inward of the outer diameter of the feed surface so that the feedable distance between the feed start position and the sheet stop portion is larger than the detectable distance as the maximum distance between the detectable position at which the sheet can be detected by the sheet detection mechanism and the sheet stop portion.