PURPOSE: To enable simple and low-cost improvemet of resistance to earthquake and strength, by a method wherein a pit serving as a pump installation foundation is built integrally with a separately structured barrel by using reinforced concrete.

CONSTITUTION: A barrel 2 on the suction side is built in the shape of a container, provided in a plane-like upper surface 10 with an opening part 11, by using reinforced concrete. A lining 12 of an airtight member is applied on the inner surface of the barrel 2 in a manner to be adhered to concrete, and a suction nozzle 6 is situated to the side of the barrel. A base plate 5 is placed on the upper end surface 10 of the barrel 2 is a manner to cover the opening part 11 therewith, and with this state a column 7 of a vertical pump 1 is inserted with a pump's suction port 8 down, and a motor 4 and a delivery port 9 are positioned externally of the barrel 2 and thereabove. This constitution enables the barrel 2 itself to form a reinforced concrete structure, and the whole is supported in earth, resulting in improvement of a vibration isolating effect.