When a retard roller is rotating in a sheet feeding direction, the rotation is transmitted to a pickup roller and the pickup roller rotates in a direction for conveying the sheet. When the retard roller is rotating in a direction opposite to the sheet feeding direction or is stationary, the pickup roller does not feed the sheet. Therefore, in a successive feeding operation, the sheet to be fed next is always conveyed such that the leading end thereof reaches a nip position between a feed roller and the retard roller. Therefore, the intervals between the sheets are uniform in the successive feeding operation.