The construction and performance of a modular hadron calorimeter for NA61 experiment at CERN are described. The calorimeter consists of individual lead/scintillator sandwich modules with the sampling satisfying the compensating condition. The light from the individual scintillator tiles is captured and transported with the WLS-fibers embedded in the scintillator grooves. The light readout is done by avalanche micro-pixel photodiodes. The construction ensures a fine transverse granulation of the calorimeter and a longitudinal segmentation of each module in 10 independent sections. The results of beam tests of the calorimeter prototype are presented.