The significant structure theory of liquids is successfully applied to the quantum liquid (3)He. The partition function uses the Debye partition function for the solid-like molecules and the Fermi-Dirac partition function for the gas-like degrees of freedom. To evaluate the gas-like partition function, numerical calculations are performed and some integral functions appearing in the equation of state of the ideal Fermi-Dirac gas are tabulated. In the solid-like molecules, the molar volume V(s) depends on the temperature, and a linear dependence is used.The thermodynamic properties, such as molar volume, vapor pressure, entropy, heat capacity, and the critical constants as well as the surface tension of liquid (3)He are calculated. The agreement between theory and experiment is satisfactory.