A sheet handling apparatus is provided, which is comprised of a plurality of inserter trays for stacking thereon insert sheets to be inserted between recording sheets having images formed thereon. Sheet feeding modes for feeding insert sheets include two kinds, i.e. S-stacking mode and F-stacking mode, that can be set by a mode key displayed on a sheet feeding mode setting screen view. In the S-stacking mode, only first-page insert sheets are stacked on a first inserter tray, and only second-page insert sheets and third-page insert sheets are stacked on second and third inserter trays, respectively. In the F-stacking mode, insert sheets are stacked in order of page on an inserter tray. Sheet feeding is suitably controlled by stacking insert sheets on inserter trays in manners corresponding to respective selected stacking modes.