A liquid tank holding mechanism for detachably holding a liquid tank to a main body portion includes a biasing member, a cover and a lever, wherein: the biasing member biases the liquid tank in a disengaging direction with the liquid tank mounted; the lever includes a lock, a biasing portion, a shaft, and a retainer and is attached to the cover pivotally around the shaft; when the retainer abuts the retainer catch, a center of the shaft is placed so as to be closer to the bearing region than is the shortest line linking a tip of the first bearing portion and a tip of the second bearing portion.