A metal atomizing device includes a casing with an inlet tube for providing liquid metal into the casing and an outlet is defined through the casing. The inlet tube and the outlet share a common axis. A polygonal impact member is located at an outlet of the inlet tube and a plurality of gas inlets are connected to the casing so as to provide noble gas into the casing and mixed with the liquid metal that impacts on the impact member. A collection member is located at the outlet of the casing and a pipe communicates with the collection member and the inlet tube so as to send the larger particles into the casing.