Although the preparation of lamellar mesoporous materials (LMMs) is very difficult due to collapsion in removing the templating surfactant, we have successfully synthesized a novel functionalized LMM film by supporting the silica layers with pillars. The interlayer distance is adjustable so as to be double of the length of the functional group, which consists of a hydrophilic and hydrophobic part. Thus, the unbound hydrophilic parts are expected to form a monolayer of water at the middle of the two adjacent silica layers in wet atmosphere. However, there are no experimental evidences to support the presence of the water monolayer. We, therefore, wish to propose a neutron reflectivity (NR) experiment for the LMMs with various humidity conditions, because NR is the only technique to provide distribution of the water in the LMM.