there is provided a method of manufacturing a multilayer ceramic substrate , the method including : providing a non - sintered multilayer ceramic substrate having a plurality of low temperature sintering green sheets laminated therein ; disposing a hard - to - sinter constraining green sheet on at least one of top and bottom surfaces of the non - sintered multilayer ceramic substrate ; sintering the non - sintered multilayer ceramic substrate having the hard - to - sinter constraining layer disposed thereon ; immersing the sintered multilayer ceramic substrate into an acidic solution ; and activating a contact between the hard - to - sinter constraining layer and the acidic solution such that the hard - to - sinter constraining layer is removed .