Cosmology is a very old science. It's goal is to describe the Universe at large scales. The standard model of cosmology is an inflation- CDM Big-Bang model. It is based on General Relativity. The cosmic microwave background is one of the three pillars of this model, with the expansion of the Universe and the primordial nucléosynthesis. It is the oldest detectable radiation in the Universe. The study of its temperature and polarisation anisotropies allow us to acess direct informations about the content and the geometry of the primordial Universe. The Planck satellite, launched on May the 14th of 2009, represents the third generation of satelite missions which study the cosmic microwave background. The exceptional sensitivity of its instruments, High Frequency Instrument and Low Frequency Instrument, will allow us to constrain very strongly the cosmological models describing the early Universe, particularly the inflationary period, and to measure the cosmological parameters which describe the evolution of the Universe with an accuracy down to the percent. To reach these ambitious scientific objectives, each systematic instrumental effect has to be severely controlled and corrected by the data analysis. The effect of cosmic rays interacting with the bolometers of HFI, which is one of the most important effects, and which differs significatively from predictions, is corrected during the time ordered data analysis. The detailed understanding of this phenomenon and its modelisation are necessary to correct it and to reach an optimal effective sensitivity. They will permit to take this effect into account in the conception of the futur instruments detectors. This thesis proposes a first part focused on cosmology, a second part describing the Planck satellite, the HFI instrument and particularly its detectors and a third part dedicated to the HFI instrument data analysis. I concentrate on time ordered data analysis and on the corrections of instrumental systematic effects. Then I propose a detailed analysis of the effect of cosmic rays on the signal and an evaluation of its impact on Planck's results.
