Can inner surface coating method

A can inner surface coating method for coating an inner surface of a bottomed cylindrical body that becomes a barrel of a can or a bottle can, comprising:

• an opening part coating step, in which a first coating material is sprayed onto an inner surface area of an opening part of the bottomed cylindrical body, while the bottomed cylindrical body is in a horizontal position and being rotated around an central axis of the bottomed cylindrical body;
• a barrel part coating step, in which, after the opening part coating step, a second coating material is sprayed onto an inner surface area of a barrel part of the bottomed cylindrical body, while keeping the bottomed cylindrical body in the horizontal position and in the state of being rotated around the central axis of the bottomed cylindrical body;
• and
• a vaporizing step, in which, after the barrel part coating step and before vaporization of volatile components of the second coating material sprayed onto the inner surface area of the barrel part of the bottomed cylindrical body, the rotation of the bottomed cylindrical body around the central axis is stopped and the position of the bottomed cylindrical body is changed from the horizontal position to a vertical position, then the volatile components of the second coating material are made to vaporize,
• wherein, the first coating material is a coating material of synthetic resin that contains a larger amount of non-volatile components than the second coating material.