The invention provides an apparatus for coating a web which has a first surface having been coated and a second surface opposite to the first surface. A support roll has a supporting surface around which the web is adapted to be conveyed and an air-jetting device for jetting air through the supporting surface onto the first surface of the web so that the web is supported by air without coming into contact with the supporting surface. A coater is disposed to face the supporting surface so as to coat the second surface of the web. The apparatus is provided with a heater for heating air to be jetted by the air-jetting device so that the temperature of the air becomes higher than that of the first surface of the web.