A tire including, in a tread surface, a plurality of land portions partitioned by at least one internal circumferential main groove (31a, 32a) extending in a vehicle-installed inside half portion continuously in a tire circumferential direction, on at least one side in a tire width direction, and comprising, in an internal land portion (42a, 43a) located in said vehicle-installed inside half portion to a tire equatorial plane among the plurality of land portions, an internal resonator including a first auxiliary groove that terminates in the internal land portion (42a, 43a), and a first branch groove (52a, 52b) that communicates between the first auxiliary groove and the internal circumferential main groove (31a, 32a), wherein in the first branch groove (52a, 52b), a hidden groove having an opening width in the tread surface that is smaller than a groove width of a groove bottom is provided adjacent to the first auxiliary groove, wherein the hidden groove in the first branch groove comprises an opening side portion having a groove width maintained on an inner side in the tire radial direction (a groove width direction) in the same manner as in an opening width (W52aH) in the tread surface, and a groove bottom side portion having a groove width that is larger than the opening width (W52aH) and continuous in the groove depth direction, in order from a tread surface side, the groove width of the groove bottom side portion of the hidden groove gradually increases to a vicinity of a middle of the groove bottom side portion in a region from the tread surface side toward a groove bottom side, and then gradually decreases or is maintained constant in a region from the vicinity of the middle of the groove bottom side portion to the groove bottom, and an extension length in the tire radial direction of the opening side of the hidden groove is shorter than that of the groove bottom side, characterized in that the tire comprises at least two circumferential main grooves, wherein a groove width of the circumferential main groove on a vehicle-installed innermost side is maximum among the circumferential main grooves. the hidden groove in the first branch groove comprises an opening side portion having a groove width maintained on an inner side in the tire radial direction (a groove width direction) in the same manner as in an opening width (W52aH) in the tread surface, and a groove bottom side portion having a groove width that is larger than the opening width (W52aH) and continuous in the groove depth direction, in order from a tread surface side, the groove width of the groove bottom side portion of the hidden groove gradually increases to a vicinity of a middle of the groove bottom side portion in a region from the tread surface side toward a groove bottom side, and then gradually decreases or is maintained constant in a region from the vicinity of the middle of the groove bottom side portion to the groove bottom, and an extension length in the tire radial direction of the opening side of the hidden groove is shorter than that of the groove bottom side, characterized in that the tire comprises at least two circumferential main grooves, wherein a groove width of the circumferential main groove on a vehicle-installed innermost side is maximum among the circumferential main grooves.