To provide a washing machine which can easily measure the state of washing liquid without significant change of circulation pathway mechanism.

The washing machine includes an intake 5 which is connected with the bottom of an outer tub 2 and fed with washing liquid, a circulation pathway 9 which has an end connected to the intake, a discharge port 8 which communicates with the other end of the circulation pathway and brings the washing liquid back into the outer tub, and a wash liquid state detecting means 10 which detects the state of the washing liquid which passes through the circulation pathway. The washing liquid state detecting means is installed in a lateral flow path 9a of the circulation pathway and makes detection in the lower position of the cross section of the flow path avoiding the upper place.