A shrinkage suppression layer used in the production of a ceramic substrate according to a non-shrinkage process provides favorable removal performance while sufficiently ensuring the restraining performance of the shrinkage suppression layer. Resin beads, which disappear at a temperature lower than the sintering temperature of a low-temperature sintering ceramic material of a base material layer to form open bores in a shrinkage suppression layer, are added to the shrinkage suppression layer and dispersed uniformly at least in a principal surface direction. The shrinkage suppression layer provides sufficient restraining performance to the base material layer in the step of firing, and after the firing, forms open bores, thereby improving the removal performance of the shrinkage suppression layer.