  For the microwave equivalent of "light shining through the wall" (LSW)
experiments, a sensitive microwave detector and very high electromagnetic
shielding is required. The screening attenuation between the axion generating
cavity and the nearby detection cavity should be greater than 300 dB, in order
to improve over presently existing exclusion limits. To achieve these goals in
practice, a "box in a box" concept was utilized for shielding the detection
cavity, while a vector signal analyzer was used as a microwave receiver with a
very narrow resolution bandwidth in the order of a few micro-Hz. This
contribution will present the experimental layout and the results to date.
