Provided is a nanotube-polymer composite which can effectively utilize characteristics of a carbon nanotube structure. The composite includes a carbon nanotube structure and a polymer, in which: the carbon nanotube structure has a network structure constructed by mutually cross-linking functional groups bonded to multiple carbon nanotubes through chemical bonding of the functional groups together; and the polymer is filled in the network structure. Also provided is a method of manufacturing a composite which includes the steps of: supplying a base body surface with a solution containing multiple carbon nanotubes to which multiple functional groups are bonded; mutually cross-linking the multiple carbon nanotubes through chemical bonding of the multiple functional groups together to construct a network structure constituting a carbon nanotube structure; impregnating the network structure with a polymer liquid forming a polymer; and combining the carbon nanotube structure and the polymer by curing the polymer liquid.