To provide a reflector antenna, having lightweight and high stiffness for suitable mounting on an artificial satellite and being easily manufactured.

Among a plurality of fibers 11 to 13, each being used in one of triaxial directions collectively composing triaxial fabric 10, a pair of conductive fibers 12A are used to be disposed with a predetermined distance in one predetermined axial direction of the fibers 12, and other dielectric fibers 12B are used to be disposed between the pair of the conductive fibers. This enables realization of reflection characteristics of radio waves and selectivity (polarization filter), with respect to the reflection direction of the radio wave.