To form an insulation film of low heat history and proper coverage.

When forming the insulation film on a semiconductor substrate 10 in a reaction chamber 100, a flow rate of SiH4 gas at a reaction gas inlet port 1 is set to 0.1 sccm to 100 sccm, a flow rate of an NH3 gas at a reaction gas inlet port 2 is set to 10 sccm to 1,000 sccm, the pressure of the reaction chamber 100 is set to 0.01 Pa to 0.1 Pa, a heating temperature of a W wire (catalytic substance) 3 is set to 1,800°C to 2,000°C, a distance d from the catalytic substance to the substrate 10 is set to 60 mm to 300 mm, and the heating temperature of a substrate heater 5 is set to 500°C to 700°C. Under these processing conditions, the distance between the catalytic substance 3 and the substrate 10 is larger and a film-forming pressure is lower than the conventional film- forming conditions, increasing a mean free path of a reaction gas while suppressing the gas phase reaction thereof, resulting in the formation of an insulation film having prosper coverage. Furthermore, a high heating temperature of the substrate 10 is also an attribute to the formation of the insulation film having proper coverage.