To provide a reactor capable of reducing the manufacturing cost of the apparatus and almost completely eliminating the retention of a precipitate precipitated by a reaction of a first reactive liquid with a second reactive liquid.

The reactor (10) which is constituted so that at least two reactive liquids of the first reactive liquid (L1) and the second reactive liquid (L2) are reacted with each other and a product (L3) produced by the reaction is discharged from a discharge part (330), is provided with: a flow passage (33) for circulating the first reactive liquid (L1) toward the discharge part (330); a first reactive liquid supplying means (40) for introducing the first reactive liquid (L1) into the flow passage (33); and a liquid mist jetting means (60) for jetting the second reactive liquid (L2) as a liquid mist (M) of an atomized state toward the first reactive liquid (L1) circulating in the flow passage (33) from above the flow passage (33).