To investigate the industrial availability of liquid fermentation (PL-ferment) by Phellinus linteus mycelium as a postbiotics for the inhibition of inflammation, PL-ferment was fractionated into culture supernatant (CS), hot-water extract (HW) from PL-ferment, EtOH-precipitate (CP) fractionated from HW, and the dialysate (DCP) of CP. Compared to the other fractions, DCP which is expected to contain exopolysaccharide (EPS) as the major component, significantly decreased the production of NO, IL-6, and MCP-1 in LPS-induced RAW 264.7 cells, and IL-6 and IL-8 in TNF-α and IFN-γ-induced HaCaT cells. The general component analysis results showed that no significant difference in components was observed between the fractions, whereas sugar composition analysis revealed that DCP had decreased glucose and increased mannose contents compared to the other fractions. This suggests that mannose played an important role in the anti-inflammatory activity of the active fraction, DCP. Molecular weight distribution analysis revealed that DCP was mainly composed of low-molecular-weight material-removed high-molecular-weight polysaccharides of 18–638 kDa, suggesting that EPS originated from P. linteus EPS. In conclusion, our results suggest that the DCP of P. linteus mycelium fermentation using the anti-inflammatory activity could be used industrially as postbiotic material.