There is disclosed a method for the production of a three-dimensional product (2) via an additive layer manufacturing process such as an electron beam manufacturing process to selectively fuse parts (17) of a powder bed (16), said parts (17) corresponding to successive cross-sections of the product (2). The method involves the use of said additive layer manufacturing process to form a tool (12) by selectively fusing additional parts (18) of the powder bed (16), said additional parts (18) corresponding to successive cross-sections of the tool (12). The method also comprises a subsequent step of manipulating the tool (12) perform a processing function on the product (2).