A nitride film manufacturing method for forming a nitride film (70, 70a, 90a, 90b) on a substrate provided in a chamber by a plasma CVD technique, the method comprising the steps of: obtaining distribution of a refractive index of the nitride film (70, 70a, 90a, 90b) and/or distribution of a deposition rate of the nitride film (70, 70a, 90a, 90b) within a predetermined numerical range, using first high-frequency power having a relatively high frequency and/or second high-frequency power having a relatively low frequency, the first high-frequency power and the second high-frequency power being applied independently for forming the nitride film (70, 70a, 90a, 90b), such that the second high-frequency power is applied while the first high-frequency power is not applied and the first high-frequency is applied while the second high-frequency power is not applied; and calculating a first period for applying the first high-frequency power and a second period for applying the second high-frequency power in order to obtain desired compressive stress or tensile stress including a case where the stress is zero of the nitride film (70, 70a, 90a, 90b), based on the following (a) and (b): (a) the distribution of the refractive index of the nitride film (70, 70a, 90a, 90b) and/or the distribution of the deposition rate of the nitride film (70, 70a, 90a, 90b), (b) the ratio between the first period and the second period; independently controlling a first high-frequency power source arranged to apply the first high-frequency power of a relatively high frequency power to a shower head gas importer and generate a first plasma from the gas discharged from the shower head gas importer according to the calculated first period; independently controlling a second high-frequency power source arranged to apply the second high-frequency power of a relatively low frequency power to the shower head gas importer and generate a second plasma from the gas discharged from the shower head gas importer. obtaining distribution of a refractive index of the nitride film (70, 70a, 90a, 90b) and/or distribution of a deposition rate of the nitride film (70, 70a, 90a, 90b) within a predetermined numerical range, using first high-frequency power having a relatively high frequency and/or second high-frequency power having a relatively low frequency, the first high-frequency power and the second high-frequency power being applied independently for forming the nitride film (70, 70a, 90a, 90b), such that the second high-frequency power is applied while the first high-frequency power is not applied and the first high-frequency is applied while the second high-frequency power is not applied; and calculating a first period for applying the first high-frequency power and a second period for applying the second high-frequency power in order to obtain desired compressive stress or tensile stress including a case where the stress is zero of the nitride film (70, 70a, 90a, 90b), based on the following (a) and (b): (a) the distribution of the refractive index of the nitride film (70, 70a, 90a, 90b) and/or the distribution of the deposition rate of the nitride film (70, 70a, 90a, 90b), (b) the ratio between the first period and the second period; (a) the distribution of the refractive index of the nitride film (70, 70a, 90a, 90b) and/or the distribution of the deposition rate of the nitride film (70, 70a, 90a, 90b), (b) the ratio between the first period and the second period; independently controlling a first high-frequency power source arranged to apply the first high-frequency power of a relatively high frequency power to a shower head gas importer and generate a first plasma from the gas discharged from the shower head gas importer according to the calculated first period; independently controlling a second high-frequency power source arranged to apply the second high-frequency power of a relatively low frequency power to the shower head gas importer and generate a second plasma from the gas discharged from the shower head gas importer.