An intake sound amplifier amplifies intake sound that is transmitted from an engine mounted in an engine compartment of a vehicle to a cabin. The intake sound amplifier includes a first passage branched from an intake passage, through which intake air is introduced into an engine; a device body that includes a vibrating body vibrated by pulsation of the intake air and is connected to a downstream end of the first passage; and a second passage that is connected to a downstream end of the device body and extends to the cabin side. The device body is located outward in a vehicle width direction of a side frame that extends in a vehicle front-rear direction and separates inside of the engine compartment from outside in the vehicle width direction.