Substrate liquid processing apparatus and substrate liquid processing method

A substrate liquid processing apparatus includes a tank; a circulation line; a processing unit connected to the circulation line through a branch line and configured to perform a liquid processing on a substrate using a processing liquid flowing through the circulation line; a processing liquid producing mechanism configured to produce the processing liquid by mixing at least two kinds of raw material liquids supplied from respective raw material liquid sources at a controlled mixing ratio; a concentration measuring device configured to measure a concentration of the processing liquid flowing through the circulation line and a concentration of the processing liquid flowing through the processing liquid supply line; and a control device configured to control the processing liquid producing mechanism based on the measured concentrations of the processing liquid.