The effect of segregation of carbon on atomically clean surface of Mo(110) heated in ultrahigh vacuum on both the reflection of slow (0—50 eV) electrons by total current spectroscopy (TCS) and the work function $\varphi$ by the contact potential difference are studied. During the annealing at $Т_{anneal}$ = 1400—2000 K, the $\varphi$ value gradually decreases by $\Delta \varphi$ = 0.18 eV (up to 4.82 $\pm$ 0.02 eV), and it is accompanied by a monotonic shift of the two major minima in TCS to meet each other on $\Delta E$ = 1.2 eV to the values of $E$ = 4.8 and 12.5 eV, which are typical for the plasmon excitation in graphene in $\pi$-conduction band and ($\pi + \sigma$)-valence band, respectively. Minima indicate the electrons’ emission in the opposite direction, and their shifts are caused by energy shift of the conduction $\pi$-band upward and $\sigma$-valence band downwards. Annealing at $Т_{anneal}$ = 2200—2700 K does not change the $\varphi$ value and all parameters of the TCS, and the status of such a surface becomes thermodynamically stable for graphene on Mo(110). Graphene increases the number of peaks of electrons’ reflection from three to five, and reduces by several times the reflection coefficient, which drops almost to zero with $E$ increasing.