A liquid container can be mounted to an apparatus in which an optical sensor is installed. The liquid container has a reservoir storing a liquid, a detection chamber communicates with the reservoir and a displacement member displacing according to an amount of liquid stored in the reservoir. The displacement member has a light shielding part that moves in a first direction between a position where light of the optical sensor is shielded and a position where the light is not shielded and a regulating member regulating movement of the displacement member in a direction crossing the first direction. An inner wall of the detection chamber has a first area facing the light shielding part and transmitting the light of the optical sensor and a second area facing the regulating member. The first area and the second area are connected via a ridgeline having an inter-surface angle larger than 180 degrees.