A multi air chamber tire comprising: a tread portion ; a pair of bead portions ; a pair of sidewall portions extending between the tread portion and the pair of bead portions ; and partition walls respectively provided to half portions of a tire which are defined with respect to a tire equator plane (CL), the partition walls partitioning an inner cavity of the tire to form a plurality of air chambers disposed adjacent to each other, wherein each of the partition walls includes a first coupling portion coupled with a tire inner wall surface, and a second coupling portion coupled with the tire inner wall surface at a position outward of the first coupling portion in a tire radial direction, in a state where the tire is filled with fluid, a first air chamber is formed in a space located at a position inward of the partition walls in a tire width direction, and a second air chamber is formed in a space located between a partition wall of the partition walls and the tire inner wall surface of a sidewall portion of the pair of sidewall portions , the second coupling portion is coupled with the tire inner wall surface at a position outward of a ground contact edge of the tread portion in the tire width direction, and each of the partition walls has strength which prevents expansion and deformation of the partition wall caused by the internal pressures of the second air chambers when the second air chambers are filled with the prescribed internal pressure in a state where the first air chamber is not filled with fluid, the multi air chamber tire being characterised in that the second coupling portion is coupled with the tire inner wall surface at a position inward of the maximum width position of a belt provided in the tread portion in the tire width direction. a tread portion ; a pair of bead portions ; a pair of sidewall portions extending between the tread portion and the pair of bead portions ; and partition walls respectively provided to half portions of a tire which are defined with respect to a tire equator plane (CL), the partition walls partitioning an inner cavity of the tire to form a plurality of air chambers disposed adjacent to each other, wherein each of the partition walls includes a first coupling portion coupled with a tire inner wall surface, and a second coupling portion coupled with the tire inner wall surface at a position outward of the first coupling portion in a tire radial direction, in a state where the tire is filled with fluid, a first air chamber is formed in a space located at a position inward of the partition walls in a tire width direction, and a second air chamber is formed in a space located between a partition wall of the partition walls and the tire inner wall surface of a sidewall portion of the pair of sidewall portions , the second coupling portion is coupled with the tire inner wall surface at a position outward of a ground contact edge of the tread portion in the tire width direction, and each of the partition walls has strength which prevents expansion and deformation of the partition wall caused by the internal pressures of the second air chambers when the second air chambers are filled with the prescribed internal pressure in a state where the first air chamber is not filled with fluid, the multi air chamber tire being characterised in that the second coupling portion is coupled with the tire inner wall surface at a position inward of the maximum width position of a belt provided in the tread portion in the tire width direction. <EOS>