[(MnSe)(x)/(ZnSe)(y)](60) superlattices (x = 4-16 Angstrom, y similar to 12 Angstrom) are grown on GaAs(100) substrates by molecular beam epitaxy (MBE) and are characterized by in situ reflection high-energy electron diffraction (RHEED), X-ray diffraction (XRD), photoluminescence (PL) and photoreflectance (PR). MnSe in the superlattice structure is confirmed to be zincblende (ZB) by RHEED analysis. Lateral lattice spacings a(0 I 1) of the individual MnSe and ZnSe layers in the superlattice are measured from the interval of the RHEED streaks. The lateral lattice spacing of the superlattice with MnSe layers thinner than 4 Angstrom is fixed to that of the ZnSe buffer layer throughout the 60-period superlattice growth, that is, the superlattices grow coherently to the ZnSe buffer layer. Superlattices with thicker MnSe layers show increases in the lateral lattice spacing as the growth proceeds, and the RHEED pattern becomes spotty. Coherently grown samples show PL and PR signals due to excitonic transitions in the MnSe/ZnSe type-I superlattice. A small Stokes shift of 2meV indicates the high quality of the superlattices. The energy gap of the ZB MnSe is estimated to be 3.4eV at 13.5 K Mn-related luminescence bands are observed at 2.1 and 1.7 eV, and the intensity of the 1.7 eV band is very small in coherently grown samples.