One embodiment of the invention relates to a field effect trench transistor with a multiplicity of transistor cells that are arranged like an array and whose gate electrodes are arranged in active trenches formed in a semiconductor body. Inactive trenches are arranged in the array of the transistor cells, there being no gate electrodes situated in said inactive trenches, and a series of polysilicon diodes are integrated in one or more of the inactive trenches which diodes, for protection against damage to the gate oxide through ESD pulses, are contact-connected to a source metallization at one of their ends and to a gate metallization at their other end, and/or alternatively or additionally one or more polysilicon zener diodes connected in series is or are integrated in the inactive trench or trenches and contact-connected to the gate metallization by one of its or their ends and to drain potential by its or their other end.