Device for separating oil particles from the air flow discharged from the spindle chamber of a machine tool, comprising a filter element comprising a continuous side wall in which a filter material is received, a continuously closed bottom and a cover , wherein the side wall is fastened between the bottom and the cover, wherein an outlet for the cleaned air flow is arranged on the cover, wherein the filter element has the shape of a hollow cylinder, wherein the filter material consists of a fibre mixture of synthetic fibres and glass fibres, wherein the fibre material and the incident-flow speed of the air flow are selected such that, during the incident flow of the air flow through the filter material, the oil particles from the air flow in the filter material agglomerate on the surface of the filter material to form droplets and the droplets flow away downwards, wherein the filter material has a weight per unit of area of 90-150 g/m 2 and a thickness in the range from 0.1 mm-1 mm, characterized in that the device has a housing with an expansion chamber, an inlet for the loaded air flow , an outlet for the separated-off air flow and a drain for oil , wherein the filter element is arranged in the expansion chamber of the housing, wherein a perforated sheet is arranged as diffuser between the housing side wall and the filter element , wherein the housing has an opening on the upper side of the housing so that the filter element can be exchangeably arranged in the housing by way of the opening, wherein multiple closure elements are provided on the upper side of the housing and next to the opening in order to hold the filter element in the housing. a continuous side wall in which a filter material is received, a continuously closed bottom and a cover , wherein the side wall is fastened between the bottom and the cover, wherein an outlet for the cleaned air flow is arranged on the cover, wherein the filter element has the shape of a hollow cylinder, wherein the filter material consists of a fibre mixture of synthetic fibres and glass fibres, wherein the fibre material and the incident-flow speed of the air flow are selected such that, during the incident flow of the air flow through the filter material, the oil particles from the air flow in the filter material agglomerate on the surface of the filter material to form droplets and the droplets flow away downwards, wherein the filter material has a weight per unit of area of 90-150 g/m 2 and a thickness in the range from 0.1 mm-1 mm, characterized in that the device has a housing with an expansion chamber, an inlet for the loaded air flow , an outlet for the separated-off air flow and a drain for oil , wherein the filter element is arranged in the expansion chamber of the housing, wherein a perforated sheet is arranged as diffuser between the housing side wall and the filter element , wherein the housing has an opening on the upper side of the housing so that the filter element can be exchangeably arranged in the housing by way of the opening, wherein multiple closure elements are provided on the upper side of the housing and next to the opening in order to hold the filter element in the housing. <EOS>