A new laser calorimeter has been developed with semiconductor thermopile as the te mperature sensor. Compared with metal-wire thermopiles, they have the advantages ofhigh-sensitivity, lower electrical resistance, and the manufacture technology is simple.It can be used for the energy measurement of laser pulses at an wavelength range from 0.3 m to 10m and energies from 0.013 to 15 joules, with an absolute accuracy of 5%.