[en] Recent experiments of D-D reactions at the PF-1000 device in IPPLM Warsaw made possible to determine more exactly the time and energy distribution of produced neutrons due to ten scintillation detectors placed at distances between 7 and 85 m from the neutron source in both axial directions. In this article the de-noising of neutron signal via wavelet transformation is described. The signals were filtered with using the discrete wavelet transformation. The Mallat multiresolution algorithm was used, which divides the signal using decomposition coefficients and a hard. This method was used for filtration of the neutron signals acquired from D-D fusion reaction at the device PF 1000 in IPPLM Warsaw. We present comparison of detected and reconstructed signals and a temporal evolution of neutron energy distribution for shot No. 6573