The Swiss Environment Panel is based on a random sample of the Swiss population over 15 years of age (since 2019: 17 years) from the population register of the Federal Statistical Office (BFS/SRPH). Foreign nationals who are residents of Switzerland are also included. The respondents were invited to participate with a letter in the main language of their community. The survey could be answered on paper (since 2019: every third survey wave) or in electronic form in German, French or Italian (since 2019: or English). To be able to assess trends over time, some questions were taken from similar surveys conducted in 1994 and 2007 ("Swiss Environmental Survey" by Andreas Diekmann and colleagues). The project is designed as a panel survey, i.e. the same people will be interviewed twice a year during the years 2018-2023. 4813 people participated in the first survey and are part of the Swiss Environmental Panel. The return rate, i.e. the proportion of participants out of all those invited, is 32.2% for the first survey. The first panel refreshment took place with wave 4 in 2019, 7803 people have joined the panel. The return rate among newly contacted persons is 44.7%.