EN
In the present paper we consider the low-temperature thermodynamic properties of the quantum Heisenberg antiferromagnet on the frustrated bilayer lattice in strong magnetic fields.Under certain conditions the isolated localized magnon states (singlets on vertical bonds;simultaneous occupation of neighboring vertical bonds is forbidden) are the ground states which dominate thermodynamics and induce a behavior inherent in the well known model of hard squares on a square lattice.We focus on magnetic properties discussing the magnetization and the susceptibility of the spin model.