NOVELTY - A deposited film comprising microcrystalline silicon is formed by plasma CVD. One of conditions from high frequency power density, bias voltage, bias current, high frequency power, ratio of diluting gas flow rate to source gas flow rate, substrate temperature, pressure and inter-electrode distance, is changed between conditions for forming deposited film of microcrystalline region and deposited film of amorphous region. A deposited film is formed in the vicinity of boundary conditions under which crystal system of film changes between amorphous and microcrystalline states.    USE - For forming a deposited film useful for forming photovoltaic element such as solar cell.    ADVANTAGE - The method can optimize the conditions for forming a deposited film to strike a balance between the improvement in the conversion efficiency and the suppression of the photodegradation at a high level. The optimum conditions determined with an experimental apparatus can be easily diverted for a manufacturing apparatus. The cost of manufacturing a photovoltaic element is reduced. Solar cells having high conversion efficiency and low photodegradation ratio are obtained.    DETAILED DESCRIPTION - The deposited film comprising microcrystalline silicon is formed by plasma CVD. One of conditions from a high frequency power density (greater than 0 to less than or equal to0.5 W/cm2), a bias voltage (greater than 0 to less than or equal to150 V/cm) with respect to an inter-electrode distance, a bias current (greater than 0 to less than or equal to0.3 mA/cm2) with respect to an electrode area, a high frequency power (greater than 0 to less than or equal to3 W/standard cubic centimeter per minute (sccm)) with respect to a source gas flow rate, a ratio (greater than 0 to less than or equal to10) of a diluting gas flow rate to a source gas flow rate, a substrate temperature (greater than 0 to less than or equal to20degreesC), a pressure (greater than 0 to less than or equal to200 Pa) or an inter-electrode distance (greater than 0 to less than or equal to5 mm), is changed between conditions for forming a deposited film of a microcrystalline region and conditions for forming a deposited film of an amorphous region. A deposited film is formed under conditions within a predetermined range in the vicinity of boundary conditions under which the crystal system of the deposited film substantially changes between an amorphous state and a microcrystalline state. The boundary conditions are such that a ratio of a Raman scattering intensity due to a crystalline component of the deposited film to a Raman scattering intensity due to an amorphous component is changed from greater than or equal to3 to less than 3; or are such that both an open circuit voltage value and a short circuit current value of a photovoltaic element comprising the deposited film are changed by greater than or equal to5%.    An INDEPENDENT CLAIM is also included for a method of forming a photovoltaic element comprising unit element(s) comprising a p-type layer, an i-type layer, and an n-type layer by plasma CVD. The i-type layer is an intrinsic deposited film comprising microcrystalline silicon. The i-type layer is formed by the above method.