A replenishing-type liquid storage tank includes a tank body, a backpressure application member, and upper limit indicator set in the tank body. Liquid is replenishable in the tank body and the tank body is configured to store the liquid therein. The backpressure application member is made from a material capable of absorbing liquid and is accommodated in the tank body to apply backpressure to the liquid stored in the tank body. The upper limit indicator is indicative of a liquid level of a maximum tolerable amount of the liquid that can be stored in the tank body. The backpressure application member has a portion positioned higher than the upper limit indicator.