An ink jet recording apparatus comprising: a supply liquid tank unit; a recording head including a head portion that ejects ink onto a recording medium; and a wiper that wipes an ink ejection surface of the recording head, the recording head includes a cleaning liquid supply member provided adjacent to the head portion on an upstream side thereof with respect to a wiping direction of the wiper, the cleaning liquid supply member supplying cleaning liquid, the supply liquid tank unit includes: a supply liquid tank that contains the cleaning liquid to be supplied to the cleaning liquid supply member; and a detection sensor for detecting a liquid level of the cleaning liquid in the supply liquid tank, the supply liquid tank includes: a first chamber provided with an inflow port allowing inflow of the cleaning liquid; a second chamber provided with an outflow port allowing outflow of the cleaning liquid; a partition wall for partitioning the first chamber and the second chamber from each other; and a lower communicating path which is formed from a lower end of the partition wall and a lower surface of the supply liquid tank and which makes the first chamber and the second chamber communicating with each other, the inflow port is provided at one longitudinal end portion of the supply liquid tank, and the outflow port is provided at the other longitudinal end portion of the supply liquid tank; the outflow port is placed below the detection sensor, and the detection sensor is arranged to detect a liquid level of the cleaning liquid in the second chamber, and is placed above the lower end of the partition wall. a supply liquid tank unit; a recording head including a head portion that ejects ink onto a recording medium; and a wiper that wipes an ink ejection surface of the recording head, the recording head includes a cleaning liquid supply member provided adjacent to the head portion on an upstream side thereof with respect to a wiping direction of the wiper, the cleaning liquid supply member supplying cleaning liquid, the supply liquid tank unit includes: a supply liquid tank that contains the cleaning liquid to be supplied to the cleaning liquid supply member; and a detection sensor for detecting a liquid level of the cleaning liquid in the supply liquid tank, the supply liquid tank includes: a first chamber provided with an inflow port allowing inflow of the cleaning liquid; a second chamber provided with an outflow port allowing outflow of the cleaning liquid; a partition wall for partitioning the first chamber and the second chamber from each other; and a lower communicating path which is formed from a lower end of the partition wall and a lower surface of the supply liquid tank and which makes the first chamber and the second chamber communicating with each other, the inflow port is provided at one longitudinal end portion of the supply liquid tank, and the outflow port is provided at the other longitudinal end portion of the supply liquid tank; the outflow port is placed below the detection sensor, and the detection sensor is arranged to detect a liquid level of the cleaning liquid in the second chamber, and is placed above the lower end of the partition wall. a supply liquid tank that contains the cleaning liquid to be supplied to the cleaning liquid supply member; and a detection sensor for detecting a liquid level of the cleaning liquid in the supply liquid tank, the supply liquid tank includes: a first chamber provided with an inflow port allowing inflow of the cleaning liquid; a second chamber provided with an outflow port allowing outflow of the cleaning liquid; a partition wall for partitioning the first chamber and the second chamber from each other; and a lower communicating path which is formed from a lower end of the partition wall and a lower surface of the supply liquid tank and which makes the first chamber and the second chamber communicating with each other, a first chamber provided with an inflow port allowing inflow of the cleaning liquid; a second chamber provided with an outflow port allowing outflow of the cleaning liquid; a partition wall for partitioning the first chamber and the second chamber from each other; and a lower communicating path which is formed from a lower end of the partition wall and a lower surface of the supply liquid tank and which makes the first chamber and the second chamber communicating with each other, the inflow port is provided at one longitudinal end portion of the supply liquid tank, and the outflow port is provided at the other longitudinal end portion of the supply liquid tank; the outflow port is placed below the detection sensor, and the detection sensor is arranged to detect a liquid level of the cleaning liquid in the second chamber, and is placed above the lower end of the partition wall.