An automation field device having a housing and a modular field device electronics unit located inside the housing. The electronics unit has a first circuit board having at least one first and one second plug-in connector element, wherein the first plug-in connector element is used to electrically connect a peripheral unit, wherein both the first and the second plug-in connector elements can be contacted essentially from the same preferred plug-in direction, and a second circuit board having at least one third plug-in connector element, wherein the circuit boards are arranged such that the second plug-in connector element is connected to the third plug-in connector element in a detachable manner to electrically connect the peripheral unit to the second circuit board, and the second circuit board has at least one opening, via which the first plug-in connector element of the first circuit board is accessible for connecting the peripheral unit.