A sheet feeder incorporatable in an image forming apparatus includes a sheet container to accommodate a sheet, a sheet feeding unit, a sheet conveyance member, a sheet conveying unit disposed downstream from the sheet feeding member in a sheet conveyance direction, and a controller to stop the sheet feeding unit before the sheet abuts against the sheet conveying unit and to resume the driving, and to drive the sheet conveying unit to start while rotating the sheet feeding unit. The controller adjusts a temporary stop period for the driving of the sheet feeding unit before the sheet abuts against the sheet conveying unit, according to a period in which the sheet passes first and second points determined optionally between a standby position determined prior to feeding of the sheet and a temporary stop position located before the sheet abuts against the sheet conveying unit.