An endoscope reprocessor includes: an endoscope housing portion 4 a medicinal solution tank 58 in which a medicinal solution M is stored a medicinal solution transfer portion 65 that transfers the medicinal solution M from the medicinal solution tank 58 to the endoscope housing portion 4 a comparison portion 75 that compares the concentration of the medicinal solution M and a first reference concentration a first adjustment portion 73 that increases a reaction rate of the medicinal solution M and a control portion 70 to which the comparison portion 75 and the first adjustment portion 73 are connected, and which drives the first adjustment portion 73 in a case where the comparison portion 75 determines that the concentration of the medicinal solution M is lower than the first reference concentration.