PROBLEM TO BE SOLVED: To provide a culturing method for stably generating a large sized Lyophyllium decastes in an indoor culturing method by burying the mushroom bed of the L. decastes in a vessel, without changing the conventional culturing method. SOLUTION: In this culturing method of burying the mushroom bed of the L. decastes in the container for generating its mycelium, the method is characterized by mixing or making a plurality of mushroom beds contact with one another and arranging them in the container for fusing the mycelia.