The study investigates the magnetic properties of atomically thin Fe3GeTe2 (FGT) flakes, demonstrating that monolayer FGT exhibits robust two-dimensional itinerant ferromagnetism with strong out-of-plane anisotropy. Layer-dependent studies reveal a crossover from three-dimensional to two-dimensional Ising ferromagnetism for thicknesses less than 4 nm, with a significant drop in the Curie temperature from 207 K to 130 K in the monolayer. For thicker flakes, a peculiar magnetic behavior emerges within an intermediate temperature range, attributed to the formation of labyrinthine domain patterns. The work highlights FGT as a novel atomically thin ferromagnetic metal, offering potential for studying controllable 2D itinerant Ising ferromagnetism and engineering spintronic van der Waals heterostructures.The study investigates the magnetic properties of atomically thin Fe3GeTe2 (FGT) flakes, demonstrating that monolayer FGT exhibits robust two-dimensional itinerant ferromagnetism with strong out-of-plane anisotropy. Layer-dependent studies reveal a crossover from three-dimensional to two-dimensional Ising ferromagnetism for thicknesses less than 4 nm, with a significant drop in the Curie temperature from 207 K to 130 K in the monolayer. For thicker flakes, a peculiar magnetic behavior emerges within an intermediate temperature range, attributed to the formation of labyrinthine domain patterns. The work highlights FGT as a novel atomically thin ferromagnetic metal, offering potential for studying controllable 2D itinerant Ising ferromagnetism and engineering spintronic van der Waals heterostructures.