A strut mount capable of reducing the weight and of intensifying the strength and having a good durability is provided. It comprises an inner cylinder, a vibration isolating base body and a pair of upper and lower brackets. The lower bracket is fabricated from aluminum alloy and includes a peripheral wall portion, a bottom wall portion and a first attachment flange while the upper bracket includes a second attachment flange and a lid wall portion. The first attachment flange has plural first through-holes for inserting plural attachment members, the second attachment flange has plural second through-holes for inserting the plural attachment members, and flange portions around the first through-holes of the first attachment flange bulge at their undersides to form respective thick-walled portions.