To obtain a functional food capable of effectively ingesting a water soluble or water insoluble glucan in carpophore or mycelium of Agaricus blazei Murrill.

This functional food is obtained by milling the fructification or mycelium of Agaricus blazei Murrill into 20 to 100 mesh of grain sizes, adding water to obtain a water suspension including 20 to 90 wt.% of the grain, charging this suspension into a cylinder including 80 to 85 vol.% of a rigid body having diameters of 0.5 to 1.2 mm, rotating and milling this mixture at ≤50°C, and drying the obtained slurry.