The present invention relates to a stress measuring device (10) and method for determining a level (15) of stress of a user (1) in particular long term stress. The stress measuring device (10) comprises an input interface (12) for receiving a skin conductance signal (11) indicating the skin conductance of the user (1) the skin conductance signal (11) over time forming skin conductance trace data (13). The stress measuring device (10) further comprises a processing unit (14) for processing the skin conductance trace data (13) the processing unit (14) adapted to determine over at least a portion of the skin conductance trace data (13) values of a rise time (tr) between at least two different points of the skin conductance trace data (13) to determine a frequency distribution of the rise time (tr) values and to determine the level (15) of stress of the user (1) based on the determined frequency distribution.
