This disclosure provides an inner liner of a pneumatic tire having high adhesiveness to an adjacent rubber member, which is an inner liner (100) of a pneumatic tire including a film layer (10) having at least a gas barrier layer (11) and an adhesion layer (20) disposed on at least one side of the film layer (10), where the gas barrier layer (11) contains at least a thermoplastic resin, the adhesion layer (20) contains at least a polystyrene-based thermoplastic elastomer, and the polystyrene-based thermoplastic elastomer has a styrene content of 40 mass % to 55 mass %.