The interaction forces between the planar anchoring surfaces of a carbon microsphere and a graphite plate immersed in 8CB liquid crystal have been measured at different temperatures above the nematic-isotropic transition point, using an atomic force microscopy. The attractive force was observed between the surfaces when they came closer. The magnitude and the range of the attractive force increased with decreasing temperature. This attractive force is attributable to the confinement-induced phase separation of 8CB.