Thin film forming apparatus

A thin film forming apparatus configured to continuously deposit a thin film on a surface of a long film substrate that is delivered from an unwinding roll formed by winding the long film substrate and is running in a lengthwise direction using a sputtering method, the thin film forming apparatus, comprising:

• a vacuum chamber;
• a film depositing roll stored in the vacuum chamber and wound with a part of the running film substrate on an outer circumferential surface;
• a target material disposed so as to face the film depositing roll on an outside in a radial direction of the film depositing roll at a winding position of the long film substrate;
• a gas supply device for supplying a gas for the film deposition into the vacuum chamber;
• and
• a gas partial pressure measurement device for measuring a partial pressure of each kind of gas in the vacuum chamber,
• wherein the gas supply device includes a plurality of gas supply sections arranged side by side in a width direction of the long film substrate in the vacuum chamber and a supply amount adjustment section capable of adjusting a supply amount of the gas for each of the gas supply sections, and
• the gas partial pressure measurement device includes a plurality of measurement sections arranged side by side in the width direction of the long film substrate, and a partial pressure of the gas is measured at a position where each of the measurement sections is disposed.