A cell culture apparatus is provided with: a cell culture bag that is formed of a tubular membrane material that can accommodate cells and a culture medium therein and that has openings at both ends in the longitudinal direction, and that forms a flow passage for the culture medium from one opening toward the other opening in the longitudinal direction of the tubular membrane material; a solution supply portion that is connected to the one opening and that supplies a solution to the inside of the cell culture bag; and a solution discharge portion that is connected to the other opening and that discharges the solution from the inside of the cell culture bag.