A sheet feeding device for a document feeding apparatus includes: a sheet containing section; a lift plate for lifting sheets stacked in the sheet containing section between a sheet feeding position and a sheet loading position; a sheet feeding section for separating and feeding the sheets in the sheet feeding position one after another; and a lifting mechanism for lifting up and down the lift plate, the lifting mechanism including: a biasing member for biasing the lift plate toward the sheet feeding section; a cam, having an outer peripheral surface with a cam curve, coupled with a driving force source and being rotated thereby; and an operating lever so provided independently of and between the lift plate and the cam as to abut the outer peripheral surface of the cam and to simultaneously press the lift plate against a biasing force of the biasing member, thereby to change a posture of the lift plate between the sheet feeding position and the sheet loading position.