Abstract: In a quick connection device for piping installed with a checker (40), a connector housing (20) of a quick connector (10) is formed with opening portions (74) for inserting resilient legs (58) therein through the opening portions (74) in a direction perpendicular to an axis from leading ends of the resilient legs, and inserted portions of the resilient legs (58) are held inside the connector housing (20). The resilient legs (58) are resiliently deformed in an axially inward direction by an annular projecting portion on an outer peripheral surface of a mating pipe at insertion of the mating pipe, to unlatch latching pawls (64) of the resilient legs (58) from corresponding latch portions of the connector housing (20), whereby the checker (40) is allowed to be removed out of the connector housing (20).