A metal resistor thin-film bolometer was fabricated using the micro lithographic method and then applied to measurement of x-ray emission from gas-puff targets in the experiments at l-kJ PALS laser in Prague. The detection head with the bolometer is equipped with a precise system for its calibration. The bolometer is of 4-mu m Au capturing layer and 100 % efficiency up to 5 keV. The lowest measurable flux is 5 x 10(-9) J/cm(2).