The present invention provides a tire in which generation of partial wear and groove cracks are suppressed. Specifically, the present invention provides a tire having in a tread surface thereof plural circumferential grooves extending in the tire circumferential direction, characterized in that: each of respective circumferential grooves disposed on the outermost side in the tire widthwise direction is designed to have a section in the tire widthwise direction, in which an angle formed by a groove wall on the outer side in the tire widthwise direction, with respect to a straight line tangent to a tread contour at the opening edge on the outer side in the tire widthwise direction of said groove, is larger than an angle formed by a groove wall on the tire equatorial side in the tire widthwise direction, with respect to a straight line tangent to a tread contour at the opening edge on the tire equatorial side in the tire widthwise direction of said groove; and each of said angles is in the range of 90° to 100° (inclusive of 90° and exclusive of 100°).