The invention relates to a device for separating overspray from the booth air of coating booths, in particular painting systems, charged with overspray. The device includes a separation unit through which booth air charged with overspray can be guided and in which overspray is separated. The separating unit is designed as an exchangeable structural unit having a filter housing, an inlet opening and a filter unit. The air flow charged with overspray can be guided via the air guiding device to the separation unit. The separating unit includes an inlet collar which defines the inlet at least in sections and the air guiding device includes a connecting sleeve, which immerses in such a manner into the inlet opening when the separating device is in operation in such a manner that said connecting sleeve is surrounded by the inlet collar of the separation unit.