Studies of diffractive events performed by the H1 and ZEUS Collaborations at the HERA ep collider are presented. The data of vector meson and photon production, inclusive deep inelastic scattering and hadronic final states with open charm and jets are confronted with the predictions of the resolved Pomeron and colour dipole models. \relax

PACS numbers: 12.38.Qk, 12.40.--y, 13.60.--r