[en] The electron-proton collider HERA at DESY opened the door for the study of diffraction in real and virtual photon-proton scattering at center-of-mass energies W up to 250 GeV and for large negative mass squared -Q² of the virtual photon up to Q²=1600 GeV². At W = 220 GeV and Q²=4 GeV², diffraction accounts for about 15% of the total virtual photon proton cross section decreasing to ∼5% at Q²=200 GeV². An overview of the results obtained by the experiments H1 and ZEUS on the production of neutral vector mesons and on inclusive diffraction up to the year 2008 is presented. (orig.)