After forming a resist film from a positive chemically amplified resist material, an insolubilization treatment for making the surface of the resist film insoluble in a developer is carried out. The communication channel is segmented into independent plurality of sub-channels. A low-pressure stage blow-off two-way valve is provided in a pipe branching off midway an air pipe connecting between the high-pressure stage compressor body and the low-pressure stage compressor body, and a high-pressure stage blow-off two-way valve is provided in a pipe branching off from a discharge air pipe provided on a discharge side of the high-pressure stage compressor body. As a result, the group of separation sub-layers mitigates grain growth in the group of primary conduction sub-layers. Based on such historical and current source context factors, as well as the domain address provided in the user’s navigation request, a domain classifier consults the historical relevance data and provides the user with Web content that is identified as likely to be relevant to the user’s interests.