First principle calculation was performed on cubic manganese oxide (MnO) compound to study, electronic, magnetic, optical and transport properties via Wien2K simulation package. Spin polarized electronic calculation performed using PBE-GGA and Tb-mBJ exchange correlation functional. Density of states (DOS) and band structure calculations show the indirect band gap of 4.23 eV, which is in good agreement with its experimental value of ~ 4.44 eV. Finite value of spin polarization has been found which results in magnetic ordering (magnetic moment~ 5.00036μ_B) for the MnO. DOS also shows that the major contribution is due to Mn-3d orbitals for the states near the Fermi level along with the contribution of O-2p orbitals. Estimated optical properties (dielectric constant, refractive index, optical conductivity, absorption coefficient and energy loss) are in well correlation with our electronic properties. Optical and electronic properties of wide band gap MnO show its significance for optical devices. We have also studied the transport behavior using the BoltzTrap package which suggest the semiconducting nature of MnO compound.