Joseph-Ignace Guillotin (French: [ʒozɛf iɲas ɡijɔtɛ̃]; 28 May 1738 – 26 March 1814) was a French physician, politician, and freemason who proposed on 10 October 1789 the use of a device to carry out executions in France, as a less painful method of execution than existing methods. Although he did not invent the guillotine and opposed the death penalty, his name became an eponym for it. The actual inventor of the prototype was a man named Tobias Schmidt, working with the king's physician, Antoine Louis.
Source : Wikipedia