The working time is a structural component of the labour market. It is usually used as a tool for the measurement of the labour force engagement at work. But a distinction used to be done between the contractual working time and the effective working time. The duration of the working time could be more or less long according to the concept in use . Howlong are the durations of working time in France after the 35 hours law? How much they differ around the means ? How much these differences could be explain by the individual characteristic s ; or by characteristics of jobs and employment institutions ? We will answer to these questions through a French representative survey , which consist of 1000 peoplesample at work.Un élément structurel ca...