A lithographic apparatus comprising: - a substrate table configured to hold a substrate (S); - a projection system configured to project a beam of radiation (B) onto a target region (T) of the substrate (S); - a substrate drive mechanism configured to adjust a position (X,Y) of the substrate (S) with respect to the projection system ; - an edge mask (M) for preventing exposure of a peripheral portion (P) of the substrate (S), wherein the edge mask (M) has a radial concave edge (E) that extends over less than half a circle arch, wherein the edge mask (M) is constructed and arranged to cause a projected shadow (W) in the peripheral portion (P) when the edge mask (M) is inserted into the beam of radiation (B); - a mask carrier attached to the edge mask (M), wherein the mask carrier comprises a mask drive mechanism configured to adjust a position of the mask carrier , wherein the position is adjustable to allow the mask carrier to at least partially circumnavigate the projection system to adjust a tangential coordinate (Φ) of the edge mask (M) for inserting the edge mask (M) from a variable direction into the beam of radiation (B), and wherein the mask drive mechanism is further configured to adjust a radial coordinate (R) of the edge mask (M) for inserting the edge mask (M) at a variable distance into the beam of radiation (B); and - a controller configured to control the mask drive mechanism and programmed to coordinate the tangential and radial positions (Φ,R) of the edge mask (M) with the position (X,Y) of the substrate (S) to prevent exposure of the peripheral portion (P) of the substrate (S) during exposure of the target region (T). - a substrate table configured to hold a substrate (S); - a projection system configured to project a beam of radiation (B) onto a target region (T) of the substrate (S); - a substrate drive mechanism configured to adjust a position (X,Y) of the substrate (S) with respect to the projection system ; - an edge mask (M) for preventing exposure of a peripheral portion (P) of the substrate (S), wherein the edge mask (M) has a radial concave edge (E) that extends over less than half a circle arch, wherein the edge mask (M) is constructed and arranged to cause a projected shadow (W) in the peripheral portion (P) when the edge mask (M) is inserted into the beam of radiation (B); - a mask carrier attached to the edge mask (M), wherein the mask carrier comprises a mask drive mechanism configured to adjust a position of the mask carrier , wherein the position is adjustable to allow the mask carrier to at least partially circumnavigate the projection system to adjust a tangential coordinate (Φ) of the edge mask (M) for inserting the edge mask (M) from a variable direction into the beam of radiation (B), and wherein the mask drive mechanism is further configured to adjust a radial coordinate (R) of the edge mask (M) for inserting the edge mask (M) at a variable distance into the beam of radiation (B); and - a controller configured to control the mask drive mechanism and programmed to coordinate the tangential and radial positions (Φ,R) of the edge mask (M) with the position (X,Y) of the substrate (S) to prevent exposure of the peripheral portion (P) of the substrate (S) during exposure of the target region (T). <EOS>