We report on the density dependence of the morphology and electronic structure of zinc-blende-type MnAs dots using in situ photoemission spectroscopy combined with molecular-beam epitaxy. Transmission electron microscopy images showed the zinc-blende-type crystalline structure of 10-nm diameter for each dot on sulfur-passivated GaAs(001) surface. The valence-band photoemission spectra of the MnAs dots were similar to those of the diluted magnetic semiconductor Ga1-xMnxAs. With increasing dot density, the characteristic spectra of the zinc-blende-type MnAs persist but a weak Fermi edge appears, suggesting a metallic behavior as a result of percolation between the dots or the appearance of hexagonal MnAs as a minority phase.