Laminated film

A laminated film that comprises at least three layers of a base material layer/a covering layer/an inorganic thin film layer laminated in this order and satisfies the following requirements (a)-(d):

• (a) the base material layer comprises a resin composition that contains 70 mass % or more of polybutylene terephthalate resin;
• (b) the laminated film has a piercing strength of 0.6 N/μm or more as measured in accordance with JIS Z 1707 after having undergone a 95° C.-boiling treatment for 30 minutes;
• (c) the base material layer has a surface orientation degree of 0.144-0.160;
• and
• (d) when the value of oxygen transmission rate obtained by measuring the laminated film under a 23° C.×65% RH condition is defined as (A) and the value of oxygen transmission rate obtained by measuring same under a 40° C.×90% RH condition is defined as (B), the barrier value deterioration rate, determined by the following formula, of the laminated film is 300% or less under high-temperature and high-humidity condition.
• Barrier value deterioration rate (%)under high-temperature and high-humidity condition=(B/A)×100