A set, comprising: • a microplate, • having a rectangular first plate, • a large number of wells which are arranged in rows and columns and connected at the top to the first plate, project downward from the underside of the first plate, and have an opening on the upper side of the first plate, and • snap openings on at least two mutually opposing lateral edges of the first plate, • a lid, • having a second plate for placement onto the upper side of the first plate and for covering the openings of the wells and • snap hooks projecting from the underside of the second plate on at least two mutually opposing lateral edges of the second plate, wherein the lid rests with the second plate on the upper side of the first plate in a covering position, covers the openings of the wells, and is snapped into the snap openings by means of the snap hooks so as to form snap connections, and • an unlocking device for releasing the snap connections between the microplate and the lid, • having at least two upwardly projecting support projections (39.1-39.4) and at least one receiving portion therebetween for placing a microplate with at least two mutually opposing edge regions of the first plate onto the support projections with engagement of the wells in the at least one receiving portion and • first sliding surfaces on inner sides of the snap hooks that face one another on mutually opposing edges of the first plate and second sliding surfaces on outer sides of the support projections (39.1 - 39.4) that face away from one another on mutually opposing sides of the receiving portion, wherein the first sliding surfaces on inner sides of the snap hooks that face one another are inclined upward toward one another and/or the second sliding surfaces on outer sides of the support projections (39.1-39.4) that face away from one another are inclined upward toward one another and, when placing the microplate with snapped on lid onto the unlocking device, the snap hooks are deflected outward and the snap connections are released through sliding the second sliding surfaces on the first sliding surfaces. • a microplate, • having a rectangular first plate, • a large number of wells which are arranged in rows and columns and connected at the top to the first plate, project downward from the underside of the first plate, and have an opening on the upper side of the first plate, and • snap openings on at least two mutually opposing lateral edges of the first plate, • a lid, • having a second plate for placement onto the upper side of the first plate and for covering the openings of the wells and • snap hooks projecting from the underside of the second plate on at least two mutually opposing lateral edges of the second plate, wherein the lid rests with the second plate on the upper side of the first plate in a covering position, covers the openings of the wells, and is snapped into the snap openings by means of the snap hooks so as to form snap connections, and • an unlocking device for releasing the snap connections between the microplate and the lid, • having at least two upwardly projecting support projections (39.1-39.4) and at least one receiving portion therebetween for placing a microplate with at least two mutually opposing edge regions of the first plate onto the support projections with engagement of the wells in the at least one receiving portion and • first sliding surfaces on inner sides of the snap hooks that face one another on mutually opposing edges of the first plate and second sliding surfaces on outer sides of the support projections (39.1 - 39.4) that face away from one another on mutually opposing sides of the receiving portion, wherein the first sliding surfaces on inner sides of the snap hooks that face one another are inclined upward toward one another and/or the second sliding surfaces on outer sides of the support projections (39.1-39.4) that face away from one another are inclined upward toward one another and, when placing the microplate with snapped on lid onto the unlocking device, the snap hooks are deflected outward and the snap connections are released through sliding the second sliding surfaces on the first sliding surfaces.