  We have explored Pauli paramagnetism, Landau diamagnetism and de Haas-van
Alphen effect in a single framework, and unified these three effects for all
temperatures as well as for all strengths of magnetic field. Our result goes
beyond Pauli-Landau result on the magnetism of the 3-D ideal gas of electrons,
and is able to describe crossover of the de Haas-van Alphen oscillation to the
saturation of magnetization. We also have obtained a novel asymptotic series
expansion for the low temperature properties of the system.
