A negative-pressure-type booster includes: a booster shell attached to a support member of a vehicle; a front shell and a rear shell which constitute the booster shell; and, at the four corners of a flat part of the rear shell, linking bolts having affixed thereto protruding parts that each protrude rearward from the flat part, the protruding parts being passed through continuous connecting holes in the support member, the negative-pressure-type booster characterized in that the linking bolts are composed of upper linking bolts arranged to the upper side of the center axis of the booster shell and lower linking bolts arranged to the lower side of the center axis of the booster shell, the protruding part of either of the upper linking bolts extending farther rearward than the protruding part of the other upper linking bolt and the respective protruding parts of the lower linking bolts.