To provide a vertical type self-priming pump which reduced in restrictions on a mounting space and a mounting direction, and a vertical type self-priming pump with a filtering device which allows easy and safe filter replacement work, requires no air venting in a pump nor priming and reduced in restrictions on the mounting space and the mounting direction as compared with the case that a horizontal type pump constitution is employed.

A vertical type self-priming pump having a valveless constitution containing no check valve includes a suction port, a suction chamber, an impeller, a self-priming chamber, and a discharge port in this order from the upstream to downstream side of a flow passage, and is composed of a pump including the suction port and the discharge port above the suction chamber and an impeller, and the self-priming chamber above the suction port and the discharge port, and a drive part connected to the lower part of the pump part and serves as a driving source of the pump, wherein the rotating direction of the impeller is substantially horizontal.