Non-relativistic approach of Bohr's theory of hydrogen is revised to recapitulate memories about the salient features of atomic structure and spectral  aspect  of hydrogen atom. Since the velocity of orbital electrons is of the order of 106 m/s  and is comparable to the velocity of electromagnetic waves in free space, its relativistic variation of mass cann't be ignored. Rejuvenation of Bohr's Theory of  Hydrogen atom with the relativistic change of mass of the orbital electron predicts that the energy corresponding to any electronic transition from orbit with quantum number n2 to n1 is equal to the energy equivalent of  the relativistic variation of mass of the electron i.e.,  ΔE  =   Δmc^2 = (mn1- mn2) c^2. The transition energy of the electron in the hydrogen atom is derived in terms of wavelength of matter waves of the electron in the concerned orbits. It is shown that the atomic binding energy is exactly equal to the energy equivalent of relativistic increase of mass of the orbital electron.