In pressure bonding edible layers having irregular surfaces due to the presence of aggregated substance so that the irregular surfaces face each other, an edible layer substantially free of any aggregated substance is interposed therebetween. This allows an orally administrable edible agent of aggregated substance-containing laminate film form having a multilayer structure including laminated extremely thin layers to be produced. The multilayer structure by such a pressure bonding technique can satisfy quantitative accuracy required for pharmaceutical preparations, and prevents time constraint in a drying step or the like, thereby providing a producing method with high productivity.