A process for producing a microporous polymeric object to improve the degree of freedom for its various properties, compared to conventional processes, includes: mixing a block copolymer made of three or more kinds of segments with a polymer, wherein one or more of the segments are made of monomer units having a first functional group forming ionic and/or hydrogen bond, the segments constitute a co-continuous structure having mutually-independent and continuous regions due to a phase separation based on incompatibility between the segments, and the polymer has, at other than polymer chain terminals, a second functional group forming such bond with the first functional group, thereby allowing the segments to associate with the polymer at many points; forming a co-continuous structure including a region composed of the polymer and the segments due to the phase separation; and removing the polymer from the region by weakening the bond between the functional groups.