an object of the present invention is to provide a cell culture vessel which is simple in structure and easy to handle , and is capable of preventing damage to the cells when separated , promoting transport of nutrients and excretion of effete matter , and elevating the culturing efficiency improving effect by the structural features . in order to attain the above object , there is provided a cell culture vessel including a culture section provided with a plurality of projections having an equivalent diameter smaller than the cells to be cultured and the culture section side walls enclosing the culture section , wherein the distance between an arbitrary position on the culture section / side wall boundary line and the nearest projection is smaller than the diameter of the cells to be cultured . the effect of the projections in the vessel given to the cultured cells is enhanced .