Provided is a laminate film having a substrate and at least one thin film layer which is formed on at least one surface of the substrate, wherein at least one of the thin film layers satisfies all of the following conditions (i) to (iv): (i) silicon atoms, oxygen atoms, and carbon atoms are contained, (ii) a content ratio X (at %) of the number of carbon atoms relative to a sum of the number of silicon atoms, the number of oxygen atoms, and the number of carbon atoms is 3 to 25 at %, (iii) an average density d (g/cm3) is 2.12 g/cm3 or higher and is less than 2.25 g/cm3, and (iv) the content ratio X (at %) of the number of carbon atoms and the average density d (g/cm3) satisfy a condition represented by the following formula (1): d>(2.22−0.008X)  (1).