An antivibration device comprising: a shaft-like first fixture extending along an axis; a sleeve-like second fixture having on at least one side an opening larger than an external shape of the first fixture; an antivibration base body including a rubber elastic body and joined at least to the first fixture and the opening of the second fixture; and a restriction member secured to the second fixture for restraining the relative displacement of the first fixture; wherein the first fixture is equipped with a junction having the antivibration base body joined to an outer periphery; a flange portion connected to the junction and having the antivibration base body joined; and a stopper portion including a rubber elastic body covering the flange portion and facing the restriction member; wherein the junction is equipped with a chamfer portion where a corner connecting the flange portion and the junction is removed; a base portion connected to the chamfer portion in the axial direction; and an end portion connected to the base portion in the axial direction; and wherein at the base portion, a first projection plane made by being projected in a first direction orthogonal to the axis is substantially the same in area as a second projection plane made by being projected in a second direction orthogonal to the axis and the first direction; characterized in that the end portion is set to have the area of the second projection plane being larger than the area of the first projection plane, so that the spring constant in the first direction is smaller than that in the second direction; the flange portion is equipped with a pair of wall portions covered with the rubber elastic body and protruding in the axial direction on a side opposite to the junction to form the stopper portion; and the pair of wall portions face each other with the axis between the pair of wall portions in the first direction or the second direction. a shaft-like first fixture extending along an axis; a sleeve-like second fixture having on at least one side an opening larger than an external shape of the first fixture; an antivibration base body including a rubber elastic body and joined at least to the first fixture and the opening of the second fixture; and a restriction member secured to the second fixture for restraining the relative displacement of the first fixture; wherein the first fixture is equipped with a junction having the antivibration base body joined to an outer periphery; a flange portion connected to the junction and having the antivibration base body joined; and a stopper portion including a rubber elastic body covering the flange portion and facing the restriction member; wherein the junction is equipped with a chamfer portion where a corner connecting the flange portion and the junction is removed; a base portion connected to the chamfer portion in the axial direction; and an end portion connected to the base portion in the axial direction; and wherein at the base portion, a first projection plane made by being projected in a first direction orthogonal to the axis is substantially the same in area as a second projection plane made by being projected in a second direction orthogonal to the axis and the first direction; characterized in that the end portion is set to have the area of the second projection plane being larger than the area of the first projection plane, so that the spring constant in the first direction is smaller than that in the second direction; the flange portion is equipped with a pair of wall portions covered with the rubber elastic body and protruding in the axial direction on a side opposite to the junction to form the stopper portion; and the pair of wall portions face each other with the axis between the pair of wall portions in the first direction or the second direction.