To provide an ink liquid level detecting system capable of detecting the liquid level position of ink in an ink storage chamber at multiple levels while ensuring the degree of freedom of the disposing positions of optical detecting parts.

A detection part 91 of a swing member 90 disposed in the ink storage chamber 11 is detected by a first optical detecting part 330 and a second optical detecting part 332 disposed above the first optical detecting part 330. A floating part 92 of the swing member 90 has a first end 92A positioned the farthest from the swing center of the swing member in the floating part 92, and the detection part 91 has a second end 91A positioned the farthest from the swing center in the detection part 91. A first distance L1 between the swing center and the first end 92A is different from a second distance L2 between the swing center and the second end 91A.