PURPOSE: To prevent damage to a connecting pipe and a child pump by storing part of a liquid type object in a cylinder against the energizing force of an air cylinder by the feeding pressure of a mother pump, and feeding the stored liquid type object to said child pump by the energizing force.

CONSTITUTION: A liquid type adhesive from a mother pump 21 flows into a body 1 from the inlet port 3 of a constant pressure feeding device A and moves a slide member 4 to the side opposite to an outlet port 2 against the energizing force of an air cylinder 10. When the slide member 4 is brought to the rightmost end, the mother pump 21 is stopped due to a signal generated by a sensor 16. And, as a child pump 24 starts operation, it suck in aid discharges out the liquid type adhesive displaced by the slide member 4 which is moved to the outlet port 2 side due to the energizing force of the air cylinder 10. When the sliding member 4 is brought to the leftmost end, the mother pump 21 is operated again by a signal generated by a sensor 15. Thus, the constant pressure feeding device A serves as a buffer and high pressure is not fed to the child pump 24, without causing damage to a connecting pipe and the child pump 24.