A radiation generating apparatus comprises a fuel storage unit 20 for storing a mixed liquid 61, a pressure application unit 10 for applying a pressure to the mixed liquid 61, a jet formation unit 30 for forming a jet 61a of the mixed liquid 61, a reaction unit 44 for forming the jet 61a of the mixed liquid 61 therein, a pressure adjustment unit 41 for setting a pressure in the reaction unit 44 lower than an internal pressure of the jet formation unit 30, and a light source unit 45 for irradiating a particle group 63a with laser light L1.