A container for culturing a seed basidiospore bed comprised of pieces of wood having a half-moon shape to be inoculated with mushroom basidiospores for the culturing thereof, which comprises a thin-walled hollow cylindrical container body having a mouth for accommodating a cap at the top, said container body being separable into upper and lower sections having coupling parts, the upper section including the mouth and a shoulder part, said upper section having a cylindrical form with its diameter equal to that of the container body and its circular lower end opened, including on the outer periphery of the cylindrical coupling part a convex sectional circumferential groove, and said lower section having a cylindrical form with its circular upper end opened, including on the outer periphery of the cylindrical coupling part a convex sectional circumferential rib to engage with said circumferential groove, a barrel and a bottom of the container body being formed in one-piece continued to the underside of said coupling part, said circumferential grooves and circumferential ribs are formed in more than two steps on the upper and the lower parts respectively on said coupling parts and, one step each thereof is formed in convex and concave wave forms in section respectively so as to act as a stopgap between the coupling parts, there being a stopping flange on the lower section which restricts the mutual coupling depth in contact with the lower edge of the coupling part of said upper section on the part having the continuation of the coupling part and the barrel part of said lower section, and the lower edge of said coupling part in contact with said stopping flange is formed into an open edge which is slightly widely inclined outward.