Disclosed herein is a thermoelectric material for intermediate- and low-temperature applications, in which any one or a mixture of two or more selected from among La, Sc and MM is added to a Ag-containing metallic thermoelectric material or semiconductor thermoelectric material. The thermoelectric material has a low thermal diffusivity, a high Seebeck coefficient, a low specific resistivity, a high power factor and a low thermal conductivity, and thus has a high dimensionless figure of merit, thus showing very excellent thermoelectric properties. The thermoelectric material provide thermoelectric sensors having high sensitivity and low noise and, in addition, is widely used as a thermoelectric material for intermediate- and low-temperature applications, because it shows excellent thermoelectric performance in the intermediate- and low-temperature range.