We have fabricated a mesoporous copolymer thin film whose surface pore size can be varied from submicrometer to micrometer. Our fabrication method requires microphase separation induced by a silicone surfactant during the rapid solvent evaporation and polymerizations. The sample films were characterized with atomic force microscopy (AFM), confocal Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), in situ infrared (IR), attenuated total reflection (ATR), and other techniques. The characterization results show that the pore size can be controlled by altering the concentration of silicone surfactant. Furthermore, the mesoporous copolymer film with hydrophobic convex and hydrophilic concave structure exhibits both hydrophobic and oleophobic properties. The unique properties can be attributed to the special heterogeneous porous structure of the polymer film. The resulting porous polymer films can be utilized in many fields, such as self-cleaning, antiadhesives, adsorption, and separation. These mesoscale-patterned surfaces can also provide a model system for investigating the interface properties of actual surfaces.