A magnetic pump is provided that includes a magnet can and an impeller that are individually formed, that is capable of easily performing assembling/disassembling, that has high workability during manufacturing or maintenance, and that has high strength in a connection part between the magnet can and the impeller, and to provide a rotary body for the magnetic pump. Particularly, the fitted connection part between the magnet can and the impeller is a spigot ferrule that has a simple structure and that is firmly connectable, and a cutout portion and a convex portion are formed at a part at which an innermost part of a socket and a front end part of a spigot face each other, and the connection strength can be further heightened by twisting and turning the spigot-ferrule part, and the return of a turned state of the spigot-ferrule part is prevented by fitting the restraining member into a gap generated behind the convex portion in the turning direction of the convex portion that has entered the cutout portion and the cutout portion, and therefore the fitted connection part is never loosened.