A tire comprising: a tread portion having a tread surface and provided with a circumferential groove extending continuously in the tire circumferential direction, the circumferential groove having a groove bottom and a pair of groove walls extending radially outwardly from the groove bottom toward the tread surface , wherein the groove bottom is provided with groove bottom raised portions protruding radially outwardly from a groove bottom reference plane which is defined by a plane being parallel to the tread surface and positioned at a deepest position of the circumferential groove , the groove bottom raised portions include a first groove bottom raised portion located on a first side (s1) in a width direction of the circumferential groove , and a second groove bottom raised portion located on a second side (s2) in the width direction of the circumferential groove, and each of the first groove bottom raised portion and the second groove bottom raised portion comprises a plurality of repeating units each comprising a first bottom surface extending substantially in the tire radial direction, and a second bottom surface inclined with respect to the tire radial direction at a larger angle than the first bottom surface , and the direction of the inclination of the second bottom surface of the first groove bottom raised portion is opposite to the direction of the inclination of the second bottom surface of the second groove bottom raised portion characterized in that the first bottom surface is inclined at an angle in a range from -10 degrees to +10 degrees with respect to the tire radial direction. a tread portion having a tread surface and provided with a circumferential groove extending continuously in the tire circumferential direction, the circumferential groove having a groove bottom and a pair of groove walls extending radially outwardly from the groove bottom toward the tread surface , wherein the groove bottom is provided with groove bottom raised portions protruding radially outwardly from a groove bottom reference plane which is defined by a plane being parallel to the tread surface and positioned at a deepest position of the circumferential groove , the groove bottom raised portions include a first groove bottom raised portion located on a first side (s1) in a width direction of the circumferential groove , and a second groove bottom raised portion located on a second side (s2) in the width direction of the circumferential groove, and each of the first groove bottom raised portion and the second groove bottom raised portion comprises a plurality of repeating units each comprising a first bottom surface extending substantially in the tire radial direction, and a second bottom surface inclined with respect to the tire radial direction at a larger angle than the first bottom surface , and the direction of the inclination of the second bottom surface of the first groove bottom raised portion is opposite to the direction of the inclination of the second bottom surface of the second groove bottom raised portion characterized in that the first bottom surface is inclined at an angle in a range from -10 degrees to +10 degrees with respect to the tire radial direction. <EOS>