A cell culture device characterized by comprising: a porous polymer film; a cell culture part that accommodates the porous polymer film; a liquid storage part that stores the cell culture part therein; a medium supply means disposed on an upper part of the liquid storage part; an inverted U-shaped tube communicating with a bottom part of the liquid storage part; a medium recovery means provided below the other end of the inverted U-shaped tube; and a medium discharge means disposed on the medium recovery means; wherein the porous polymer films are a three-layer structure porous polymer film having a surface layer A and a surface layer B, the surface layers having a plurality of pores, and a macrovoid layer sandwiched between the surface layers A and B; wherein an average pore diameter of the pores present in the surface layer A is smaller than an average pore diameter of the pores present in the surface layer B; wherein the macrovoid layer has a partition wall bonded to the surface layers A and B, and a plurality of macrovoids surrounded by such a partition wall and the surface layers A and B; wherein the medium supply means is set at a position higher than the cell culture part, and a top part of the inverted U-shaped tube is set at the same height as the top of the cell culture part or at a position lower than the medium supply means; and wherein when the liquid surface of the medium supplied to the liquid storage part from the medium supply means reaches the top part of the inverted U-shaped tube, the medium is intermittently discharged into the medium recovery means due to the siphon principle. a porous polymer film; a cell culture part that accommodates the porous polymer film; a liquid storage part that stores the cell culture part therein; a medium supply means disposed on an upper part of the liquid storage part; an inverted U-shaped tube communicating with a bottom part of the liquid storage part; a medium recovery means provided below the other end of the inverted U-shaped tube; and a medium discharge means disposed on the medium recovery means; wherein the porous polymer films are a three-layer structure porous polymer film having a surface layer A and a surface layer B, the surface layers having a plurality of pores, and a macrovoid layer sandwiched between the surface layers A and B; wherein an average pore diameter of the pores present in the surface layer A is smaller than an average pore diameter of the pores present in the surface layer B; wherein the macrovoid layer has a partition wall bonded to the surface layers A and B, and a plurality of macrovoids surrounded by such a partition wall and the surface layers A and B; wherein the medium supply means is set at a position higher than the cell culture part, and a top part of the inverted U-shaped tube is set at the same height as the top of the cell culture part or at a position lower than the medium supply means; and wherein when the liquid surface of the medium supplied to the liquid storage part from the medium supply means reaches the top part of the inverted U-shaped tube, the medium is intermittently discharged into the medium recovery means due to the siphon principle. wherein the porous polymer films are a three-layer structure porous polymer film having a surface layer A and a surface layer B, the surface layers having a plurality of pores, and a macrovoid layer sandwiched between the surface layers A and B; wherein an average pore diameter of the pores present in the surface layer A is smaller than an average pore diameter of the pores present in the surface layer B; wherein the macrovoid layer has a partition wall bonded to the surface layers A and B, and a plurality of macrovoids surrounded by such a partition wall and the surface layers A and B; wherein the medium supply means is set at a position higher than the cell culture part, and a top part of the inverted U-shaped tube is set at the same height as the top of the cell culture part or at a position lower than the medium supply means; and wherein when the liquid surface of the medium supplied to the liquid storage part from the medium supply means reaches the top part of the inverted U-shaped tube, the medium is intermittently discharged into the medium recovery means due to the siphon principle.