The present invention provides a novel extract solution for cell-free protein synthesis, which contains at least an extract derived from a Bombyx mori L. tissue and an exogenous mRNA, which is easy to prepare and which is capable of realizing cell-free protein synthesis that can synthesize glycoprotein, a cell-free protein synthesis method using it, and a method for preparing an extract solution for cell-free protein synthesis, which includes adding an exogenous mRNA to an extract derived from a Bombyx mori L. tissue.