The present invention provides: a rubber composition prepared by mixing 60 to 100 parts by mass of a filler (B), 0.9 to 2.4 parts by mass of a phenol resin (C), 0.07 to 0.2 parts by mass of a methylene donor (D), 1.5 to 2.1 parts by mass of a thiuram based vulcanization accelerating agent (E), and 3.2 to 4.5 parts by mass of a sulfenamide based vulcanization accelerating agent (F), based on 100 parts by mass of the rubber component comprising 20 to 80% by mass of a modified conjugated diene based polymer (A), allowing the ride comfort in normal running to be satisfied in parallel with improvement in the run flat durability (durability in run flat running); and a tire comprising at least one member selected from the group consisting of a side reinforcing rubber layer and a bead filler using the rubber composition.