An air conditioner has an air conditioning unit for conditioning air to be introduced into a passenger compartment. The air conditioning unit has an air passage, an air conditioning case defining at least a part of the air passage and a noise absorbing member having a multi-layer structure. The noise absorbing member defines at least a part of the air passage. The noise absorbing member has an unbreathable middle layer, a first noise absorbing layer on an inner side of the middle layer and a second noise absorbing layer on an outer side of the middle layer. The second noise absorbing layer has a hardness greater than that of the first noise absorbing layer to maintain the shape of the noise absorbing member. Also, an air conditioner duct is formed of the multi-layer structure.