Introduction - Social distancing measures of varying strictness have been in place since March 17, 2020 (the date the first lockdown was implemented) to limit the spread of SARS-CoV-2. These measures have affected working conditions to varying degrees. As a result, new sources of risk to mental health may have emerged. This study aimed to track changes in anxiety and depression among the employed workforce and to identify the most affected subgroups. It represents a first step in developing targeted interventions. Methods - The data come from the Coviprev survey of the general population. During each survey wave, an independent sample of 2,000 people aged 18 and older residing in metropolitan France was surveyed via the Internet. For this study, only employed individuals were selected (those working on-site, from home, on partial unemployment, or on sick leave). This population represented between 52% and 55% of the total sample, depending on the wave considered. The data presented in this article are from waves 1 (March 23–25) through 19 (December 14–16, 2020). Results - The prevalence of anxiety symptoms was 30.5% in wave 1. It then declined significantly through wave 3 (April 14–16) before remaining at stable but relatively high levels. For depression, the prevalence was 20.9% in wave 2. It decreased significantly during the period of reopening before rising significantly again in October around the time of the second lockdown. Regarding work arrangements: being on sick leave was associated with an increased risk of experiencing an anxiety disorder compared to working on-site, but only for men. For both genders, working on-site was associated with a lower risk of experiencing a depressive state compared to working from home, being on short-time work, or being on sick leave. Sector-specific analyses highlight a higher risk of experiencing an anxiety disorder among workers in the financial and insurance sectors, and in the arts, entertainment, and recreational activities sectors. Conversely, this risk was lower for workers in human health and social work, public administration, and professional and scientific activities. The risk of experiencing a depressive state was higher among education workers and lower among workers in the human health and social work sector. Conclusions - Our results show that the prevalence of anxiety and depressive symptoms remained high throughout 2020 among the employed population. It appears that particular attention should be paid to certain population groups, such as those on sick leave, and more broadly to workers in the arts, entertainment, and recreation sectors, as well as in education.