An efficient method of deconvolution of the internal bremsstrahlung (IB) spectra accompanying the b-decay in 32 P, 85 Kr and 143 Pr is presented. Experimental data is taken from the literature. The usual experimental values are folded with the response matrix of the detector system, and the Gold iteration technique is employed to deconvolve the detector response function for the continuous IB photon spectra. The response function of the detector is calculated using the peak to total ratio and the energy resolution of the detector. The results of the deconvolved IB spectra along with the theoretical calculations are presented.