The invention provides a cell culture vessel with a coating which inhibits adhesion of a peptide relating to cell proliferation on at least a part of the surface thereof. The coating desirably contains a copolymer containing a recurring unit which contains a group represented by formula (a) and a recurring unit which contains a group represented by formula (b). wherein Ua1, Ua2, Ua3, Ub1, Ub2, Ub3 and An− are as defined herein.