A method of selectively forming (growing or depositing) a conductor layer (7) on an exposed surface of a semiconductor substrate (2) or a conductor by using a metal halide gas and a silicon hydride gas at a ratio of a flow rate of the latter gas to that of the former gas (e.g., Si n H 2n+2 /WF₆) of 2 or less, and setting a growth temperature at 200°C or less. When a Si₃H₈ gas and a WF₆ gas, in particular, are used at the ratio of the flow rates (Si₃H₈/WF₆) of 1.0 or less, and the deposition temperature is set at 100°C to room temperature, a silicon-containing tungsten layer is selectively deposited (formed).