To provide a rubber composition for an inner liner capable of improving operation stability, low fuel consumption properties, breaking elongation, sheet workability, air cutoff property and blending cost in a good balance, to provide a pneumatic tire using the rubber composition for the inner liner as the inner liner.

A rubber composition for an inner liner contains a regenerated butyl rubber, a halogenated butyl rubber other than the regenerated butyl rubber, at least one kind of weak reinforced filler selected from a group consisting of a bituminous coal ground product, talc, mica and hard clay, and carbon black having N₂SA of 20 to 35 m²/g and silica having N₂SA of 40 to 120 m²/g, and has an average particle diameter of the bituminous coal ground product of 50 μm or less, the content of the regenerated butyl rubber of 5 to 30 mass%, the total content of the regenerated butyl rubber and the halogenated butyl rubber of 70 to 100 mass% in 100 mass% of the rubber component, the total content of the weak reinforced filler of 3 to 45 pts.mass, the total content of the carbon black and the silica of 20 to 60 pts.mass based on 100 pts.mass of the rubber component.