Heat exchanger, exhaust gas recirculation system and internal combustion engine

The exchanger (10) has a heat exchanger block (11) for implementation of heat exchange, and connection lines (14.1, 14.2) for supplying a working fluid (AF) to the exchanger. A working fluid-filter is brought between the heat exchanger block and the connection lines, for integration of the working fluid-filter in the exchanger. The connection lines are connected to the heat exchanger block and are connected with a connection flange (18). The working fluid-filter includes a filter area formed in flat-shape. An independent claim is also included for an exhaust gas recirculation system including a particle filter.