  We present the first results of a search for invisible axion dark matter
using a multiple-cell cavity haloscope. This cavity concept was proposed to
provide a highly efficient approach to high mass regions compared to the
conventional multiple-cavity design, with larger detection volume, simpler
detector setup, and unique phase-matching mechanism. Searches with a
double-cell cavity superseded previous reports for the axion-photon coupling
over the mass range between 13.0 and 13.9$\,\mu$eV. This result not only
demonstrates the novelty of the cavity concept for high-mass axion searches,
but also suggests it can make considerable contributions to the next-generation
experiments.
