The present invention provides a thin film with a base, which comprises a base and a thin film that is formed on the base. The thin film has a layer A which is formed using a solution that contains polycations and a layer B which is formed using a solution that contains polyanions and has a pH of 1.6-5.4.本發明提供一種附有基材之薄膜,其具備基材、及於基材上形成之薄膜,且薄膜具有使用含有多價陽離子之溶液所形成之A層,及使用含有多價陰離子且pH為1.6~5.4之溶液所形成之B層。