T Goigoux, P Ascher, B Blank, M Gerbaux, J Giovinazzo, S Grévy, T Kurtukian Nieto, C Magron, P Doornenbal, G G Kiss, S Nishimura, P-A Söderström, V H Phong, J Wu, D S Ahn, N Fukuda, N Inabe, T Kubo, S Kubono, H Sakurai, Y Shimizu, T Sumikama, H Suzuki, H Takeda, J Agramunt, A Algora, V Guadilla, A Montaner-Piza, A I Morales, S E A Orrigo, B Rubio, Y Fujita, M Tanaka, W Gelletly, P Aguilera, F Molina, F Diel, D Lubos, G de Angelis, D Napoli, C Borcea, A Boso, R B Cakirli, E Ganioglu, J Chiba, D Nishimura, H Oikawa, Y Takei, S Yagi, K Wimmer, G de France, S Go, B A Brown

In an experiment with the BigRIPS separator at the RIKEN Nishina Center, we observed two-proton (2p) emission from ^{67}Kr. At the same time, no evidence for 2p emission of ^{59}Ge and ^{63}Se, two other potential candidates for this exotic radioactivity, could be observed. This observation is in line with Q value predictions which pointed to ^{67}Kr as being the best new candidate among the three for two-proton radioactivity. ^{67}Kr is only the fourth 2p ground-state emitter to be observed with a half-life of the order of a few milliseconds. The decay energy was determined to be 1690(17) keV, the 2p emission branching ratio is 37(14)%, and the half-life of ^{67}Kr is 7.4(30) ms.