PURPOSE: To prevent ink from evaporating out of a tube and prevent bubbles from forming inside the tube by arranging in a container full of a liquid a main power section of a wriggling pump which sends a liquid out of a tube under pressure by rotation of a roller.

CONSTITUTION: Ink or a liquid with the same density as the ink is filled in a container to prevent ink inside a tube 3 from going in and out by a permeating pressure, and a main power section 2 of a wriggling pump is arranged in the container 1. Rollers 2-2 are rotated by rotation of a motor 9 of the wriggling pump, and send the ink out of the tube 3 by pressing it in a squeezing manner. In this case, by arranging the main power section 2 of the wriggling pump in said container 1, evaporation of the ink out of the tube 3 and resultant formation of bubbles inside the tube 3 can be prevented.