- We review the ion and electron heating at the quasi-perpendicular collisionless shock front. The shock width is between the typical ion length (ion drift gyroradius) and electron scale (electron inertial length) which results in the different behavior of these two species. Ions are effectively heated at the ramp and/or reflected due to the strong breakdown of adiabaticity and direct conversion of the directed flow energy into the ion gyration energy. Electrons are dragged across the shock by the electric field along the magnetic field, if the shock is not very narrow. At even smaller shock widths electrons become nonadiabatic also and the acceleration occurs along the shock normal. Because of the direct relation of the heating features to the shock scales, the former may serve a tool for additional indirect determination of the scales.