  The axion is a hypothetical particle proposed to solve the strong $CP$
problem, and also a candidate for dark matter. This non-relativistic particle
in the galactic halo can be converted into a photon under a strong magnetic
field and detected with a microwave resonant cavity. Relying on this detection
method, many experiments have excluded some mass regions with certain
sensitivities in terms of axion-photon coupling ($g_{a\gamma\gamma}$) for
decades, but no axion dark matter has been discovered to date. CAPP-8TB is an
axion haloscope experiment at IBS/CAPP designed to search for the axion in a
mass range of 6.62 to 7.04 $\mu$eV. The experiment aims for the most sensitive
axion dark matter search in this particular mass range with its first-phase
sensitivity reaching the QCD axion band. In this presentation, we discuss the
overview of the experiment, and present the first result. We also discuss an
upgrade of the experiment to achieve higher sensitivity.
