The method for cutting a food bar into slices comprises the following steps: a) a food bar (40) is disposed on a conveying device (3), to be specific, on the disposing position; b) the food bar (40) can be conveyed to a feeding device (4), and can be moved to the conveying position; c) the feeding device (4) can be used t convey the food bar (40) to the conveying position, and the food bar (40) is more inclined to the horizontal plane when being disposed on the feeding position than the conveying position; d) a rear end of the food bar (40) can be engaged and maintained by a maintaining device (6); e) the food bar (40) can be moved to a cutting device(7); f) the food bar (40) can be cut into slices continuously by the cutting device (7). In order to reduce the loss of the residual materials in the maintaining device (6), and to improve the process safety performance, the following steps can be provided: g) the above mentioned food bar (40) can be fixed by fixing elements (33,34) of a fixing device (5) during the processes of moving the food bar from the conveying position to the feeding position in at least one free vertical side, and one of the fixing elements (33,34) and the food bar can be in a shape cooperation and/or a friction connection. Therefore a device (1) is provided to performing the above mentioned method.