Copy paper feeding device for a copying apparatus which comprises a plurality of cassettes 12, 13 capable of stroing copy paper sheets and feeding means corresponding to each of cassettes 12, 13 respectively. Each feeding means is driven selectively to feed the copy paper sheets in the case where the cassettes 12, 13 store the copy paper sheets having different sizes, and each feeding means is driven in a predetermined order to feed the copy paper sheets from one cassette 12 or 13 until the cassette 12 or 13 is vacant, then feed the copy paper sheets from the remaining cassette 13 or 12 successively in the case where the cassettes 12, 13 store the copy paper sheets having a same size. The copy paper feeding device includes the means which is situated corresponding to feeding means respectively for selecting a given feeding means to be driven.