A series of perovskite-type ceramic materials Ca0.98Er0.02MnO3 (CDM) and Ca0.96Er0.02Re0.02MnO3 (Re = La, Sm, Yb) (denoted as CDM-La, CDM-Sm, CDM-Yb) which worked from 300 K to 1000 K with excellent thermoelectric properties was prepared by a sol–gel and cold-pressing method.