A door retaining device having a housing and a retaining rod which traverses it, the device including a brake housed in the housing having a brake body stressed by a corresponding compression spring towards the retaining rod. The housing is formed by several parts assembled to one another, including a guide body molded in plastic for guiding the rod, provided with a through hole which is traversed by the rod and with at least one side hole in communication with the through hole; and a receptacle, detachably plugged to the side hole of the guide body, which houses and guides the movement of the brake body towards the retaining rod through the side hole, and in which the compression spring is supported to exert its thrusting action on the brake body.