We fabricated a non-local spin valve with a thin layer of graphite with Co transparent electrodes. The spin-valve effect and spin precession were observed at room temperature. The magnitude of the mangetoresistance increases when temperature decreases. The spin-relaxation time, [Formula: see text], obtained from the fitting of the Hanle curves increases with decreasing temperature with a weak dependence [Formula: see text] while the spin-diffusion constant D decreases. At room temperature, [Formula: see text] exceeds 100 ps and the spin-diffusion length, [Formula: see text], is ∼2 μm. The temperature dependence of [Formula: see text] is not monotonic, and it has the largest value at room temperature. Our results show that multilayer graphene is a suitable material for spintronic devices.