A liquid processing apparatus includes a processing unit, a first supply route, a first device, a second supply route, a second device, a housing, and an external housing. The processing unit processes a substrate by using processing liquid including first and second processing liquids. The first supply route is for supplying the first processing liquid to the processing unit. The first device is for supplying the first processing liquid to the first supply route. The second supply route is for supplying the second processing liquid to the processing unit. The second processing liquid has higher temperature than the first processing liquid. The second device is for supplying the second processing liquid to the second supply route. The housing accommodates the processing unit. The external housing accommodates the first and second devices, and is adjacent to the housing. The external housing includes a partition wall between the first and second devices.