A pneumatic tire having a tread pattern that comprises: an inner circumferential main groove provided along the equator line having groove walls each extending in a tire circumferential direction while angles of the groove walls with respect to a contact surface vary with a predetermined amplitude; a first outer circumferential main groove positioned away from the inner circumferential main groove toward a first side in the tire width direction, said first outer circumferential main groove having groove walls each extending in a tire circumferential direction while angles of the groove walls with respect to a contact surface vary with a predetermined amplitude; a first outer lug groove extending, from the first outer circumferential main groove toward the inner circumferential main groove, partway along a region of a first land portion between the inner circumferential main groove and the first outer circumferential main groove; and - a first sipe, wherein a width of the first sipe expands toward a tread surface due to a pair of first chamfered surfaces (25a, 25b) provided on walls of the first sipe along an extension direction of the first sipe on the contact surface characterized in that the pneumatic tire further comprises a first inner lug groove extending, from the inner circumferential main groove toward the first outer circumferential main groove, partway along a region of the first land portion between the inner circumferential main groove and the first outer circumferential main groove and in that the first sipe is configured to communicate an end portion of an outer circumferential main groove side of the first inner lug groove with an end portion of an inner circumferential main groove side of the first outer lug groove. an inner circumferential main groove provided along the equator line having groove walls each extending in a tire circumferential direction while angles of the groove walls with respect to a contact surface vary with a predetermined amplitude; a first outer circumferential main groove positioned away from the inner circumferential main groove toward a first side in the tire width direction, said first outer circumferential main groove having groove walls each extending in a tire circumferential direction while angles of the groove walls with respect to a contact surface vary with a predetermined amplitude; a first outer lug groove extending, from the first outer circumferential main groove toward the inner circumferential main groove, partway along a region of a first land portion between the inner circumferential main groove and the first outer circumferential main groove; and - a first sipe, wherein a width of the first sipe expands toward a tread surface due to a pair of first chamfered surfaces (25a, 25b) provided on walls of the first sipe along an extension direction of the first sipe on the contact surface - a first sipe, wherein a width of the first sipe expands toward a tread surface due to a pair of first chamfered surfaces (25a, 25b) provided on walls of the first sipe along an extension direction of the first sipe on the contact surface characterized in that the pneumatic tire further comprises a first inner lug groove extending, from the inner circumferential main groove toward the first outer circumferential main groove, partway along a region of the first land portion between the inner circumferential main groove and the first outer circumferential main groove and in that the first sipe is configured to communicate an end portion of an outer circumferential main groove side of the first inner lug groove with an end portion of an inner circumferential main groove side of the first outer lug groove. the pneumatic tire further comprises a first inner lug groove extending, from the inner circumferential main groove toward the first outer circumferential main groove, partway along a region of the first land portion between the inner circumferential main groove and the first outer circumferential main groove and in that the first sipe is configured to communicate an end portion of an outer circumferential main groove side of the first inner lug groove with an end portion of an inner circumferential main groove side of the first outer lug groove.