Since, Penetration of s orbital is the maximum because of the closeness to the nucleus than the p, d and f orbitals
it is easier to remove 2p electron than 2s electron
Zeff∝shielding effect1
(Zeff)B>(Zeff)Be So, shielding effect is more on 2p electron of B than 2s electron of Be
So, (Be)I.E1>(B)I.E1